diff --git a/cli/bin b/cli/bin
index e9ffbbc8f..337b2f3f6 160000
--- a/cli/bin
+++ b/cli/bin
@@ -1 +1 @@
-Subproject commit e9ffbbc8f76bd7a81d8e2e5d5e90c4f51e10a71d
+Subproject commit 337b2f3f60453c3d6edd657dc201c197506647dd
diff --git a/package-lock.json b/package-lock.json
index e1292c3cd..74fd9f6f1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8,7 +8,7 @@
       "name": "stalker-xrf-engine",
       "version": "1.0.0",
       "dependencies": {
-        "xray16": "1.1.2"
+        "xray16": "1.2.2"
       },
       "bin": {
         "xrf": "cli/run.ts"
@@ -17,7 +17,7 @@
         "@jest/globals": "^29.7.0",
         "@types/ini": "^4.1.1",
         "@types/jsdom": "^21.1.7",
-        "@types/node": "^22.0.2",
+        "@types/node": "^22.10.2",
         "@typescript-eslint/eslint-plugin": "^6.21.0",
         "@typescript-eslint/parser": "^6.21.0",
         "@typescript-to-lua/language-extensions": "^1.19.0",
@@ -45,8 +45,8 @@
         "ts-jest": "^29.2.3",
         "ts-node": "^10.9.2",
         "tsconfig-paths": "^4.2.0",
-        "typescript": "^5.6.2",
-        "typescript-to-lua": "^1.27.1"
+        "typescript": "^5.7.2",
+        "typescript-to-lua": "^1.28.1"
       }
     },
     "node_modules/@aashutoshrathi/word-wrap": {
@@ -1499,12 +1499,13 @@
       "dev": true
     },
     "node_modules/@types/node": {
-      "version": "22.0.2",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.0.2.tgz",
-      "integrity": "sha512-yPL6DyFwY5PiMVEwymNeqUTKsDczQBJ/5T7W/46RwLU/VH+AA8aT5TZkvBviLKLbbm0hlfftEkGrNzfRk/fofQ==",
+      "version": "22.10.2",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.10.2.tgz",
+      "integrity": "sha512-Xxr6BBRCAOQixvonOye19wnzyDiUtTeqldOOmj3CkeblonbccA12PFwlufvRdrpjXxqnmUaeiU5EOA+7s5diUQ==",
       "dev": true,
+      "license": "MIT",
       "dependencies": {
-        "undici-types": "~6.11.1"
+        "undici-types": "~6.20.0"
       }
     },
     "node_modules/@types/semver": {
@@ -2630,10 +2631,11 @@
       "dev": true
     },
     "node_modules/cross-spawn": {
-      "version": "7.0.3",
-      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
-      "integrity": "sha512-iRDPJKUPVEND7dHPO8rkbOnPpyDygcDFtWjpeWNCgy8WP2rXcxXL8TskReQl6OrB2G7+UJrags1q15Fudc7G6w==",
+      "version": "7.0.6",
+      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
+      "integrity": "sha512-uV2QOWP2nWzsy2aMp8aRibhi9dlzF5Hgh5SHaB9OiTGEyDTiJJyx0uy51QXdyWbtAHNua4XJzUKca3OzKUd3vA==",
       "dev": true,
+      "license": "MIT",
       "dependencies": {
         "path-key": "^3.1.0",
         "shebang-command": "^2.0.0",
@@ -8049,9 +8051,9 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.6.2",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.2.tgz",
-      "integrity": "sha512-NW8ByodCSNCwZeghjN3o+JX5OFH0Ojg6sadjEKY4huZ52TqbJTJnDo5+Tw98lSy63NZvi4n+ez5m2u5d4PkZyw==",
+      "version": "5.7.2",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.7.2.tgz",
+      "integrity": "sha512-i5t66RHxDvVN40HfDd1PsEThGNnlMCMT3jMUuoh9/0TaqWevNontacunWyN02LA9/fIbEWlcHZcgTKb9QoaLfg==",
       "license": "Apache-2.0",
       "bin": {
         "tsc": "bin/tsc",
@@ -8062,9 +8064,9 @@
       }
     },
     "node_modules/typescript-to-lua": {
-      "version": "1.27.1",
-      "resolved": "https://registry.npmjs.org/typescript-to-lua/-/typescript-to-lua-1.27.1.tgz",
-      "integrity": "sha512-9MTMIyeFkl5i/eOUtVkqzW6w2SA4Sy3K+p9cJX06Y9IP7b2kKnuZH7Vkva9rCR96eVPsBqfPysLBT+mdS5Y21Q==",
+      "version": "1.28.1",
+      "resolved": "https://registry.npmjs.org/typescript-to-lua/-/typescript-to-lua-1.28.1.tgz",
+      "integrity": "sha512-4Ah8bco9X7BNrDcVUHEDDWbZL2whoUg8CCLnUJWsoopmV43aDZuEqOlhtsWAjsH+3Wq5SugYcmyFRrZ+mWyCYw==",
       "license": "MIT",
       "dependencies": {
         "@typescript-to-lua/language-extensions": "1.19.0",
@@ -8080,7 +8082,7 @@
         "node": ">=16.10.0"
       },
       "peerDependencies": {
-        "typescript": "5.6.2"
+        "typescript": "5.7.2"
       }
     },
     "node_modules/typescript-to-lua/node_modules/source-map": {
@@ -8107,10 +8109,11 @@
       }
     },
     "node_modules/undici-types": {
-      "version": "6.11.1",
-      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.11.1.tgz",
-      "integrity": "sha512-mIDEX2ek50x0OlRgxryxsenE5XaQD4on5U2inY7RApK3SOJpofyw7uW2AyfMKkhAxXIceo2DeWGVGwyvng1GNQ==",
-      "dev": true
+      "version": "6.20.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.20.0.tgz",
+      "integrity": "sha512-Ny6QZ2Nju20vw1SRHe3d9jVu6gJ+4e3+MMpqu7pqE5HT6WsTSlce++GQmK5UXS8mzV8DSYHrQH+Xrf2jVcuKNg==",
+      "dev": true,
+      "license": "MIT"
     },
     "node_modules/universalify": {
       "version": "0.2.0",
@@ -8451,11 +8454,11 @@
       "dev": true
     },
     "node_modules/xray16": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/xray16/-/xray16-1.1.2.tgz",
-      "integrity": "sha512-kYkiAUtEbyg19RrlmHqkRKyuf1GuL/iLicbonRraHii9eYsW4Fr6+MlRzEOnnm82LaTOxZ6mZ0nFjk1b46HiUw==",
+      "version": "1.2.2",
+      "resolved": "https://registry.npmjs.org/xray16/-/xray16-1.2.2.tgz",
+      "integrity": "sha512-3uVTD9yqRzRzVUg4nXfTz2Ksww7TuvpXHqv2j9Xh8HUjauzspXpqxqKZ9EE0oVkBPGnuVJDXueIOXJZXIaU2vg==",
       "peerDependencies": {
-        "typescript-to-lua": "^1.16.3"
+        "typescript-to-lua": "^1.28.1"
       }
     },
     "node_modules/xtend": {
diff --git a/package.json b/package.json
index 7629822a4..2ef688872 100644
--- a/package.json
+++ b/package.json
@@ -21,13 +21,13 @@
     "help": "ts-node -P ./cli/tsconfig.json cli/run.ts -h"
   },
   "dependencies": {
-    "xray16": "1.1.2"
+    "xray16": "1.2.2"
   },
   "devDependencies": {
     "@jest/globals": "^29.7.0",
     "@types/ini": "^4.1.1",
     "@types/jsdom": "^21.1.7",
-    "@types/node": "^22.0.2",
+    "@types/node": "^22.10.2",
     "@typescript-eslint/eslint-plugin": "^6.21.0",
     "@typescript-eslint/parser": "^6.21.0",
     "@typescript-to-lua/language-extensions": "^1.19.0",
@@ -55,8 +55,8 @@
     "ts-jest": "^29.2.3",
     "ts-node": "^10.9.2",
     "tsconfig-paths": "^4.2.0",
-    "typescript": "^5.6.2",
-    "typescript-to-lua": "^1.27.1"
+    "typescript": "^5.7.2",
+    "typescript-to-lua": "^1.28.1"
   },
   "bin": {
     "xrf": "./cli/run.ts"
diff --git a/src/engine/core/ai/combat/combat_visibility_calculation.test.ts b/src/engine/core/ai/combat/combat_visibility_calculation.test.ts
new file mode 100644
index 000000000..c484175b6
--- /dev/null
+++ b/src/engine/core/ai/combat/combat_visibility_calculation.test.ts
@@ -0,0 +1,38 @@
+import { beforeEach, describe, expect, it } from "@jest/globals";
+
+import { calculateObjectVisibility } from "@/engine/core/ai/combat/combat_visibility_calculation";
+import { weatherConfig } from "@/engine/core/managers/weather/WeatherConfig";
+import { MockGameObject } from "@/fixtures/xray";
+
+describe("calculateObjectVisibility", () => {
+  beforeEach(() => {
+    weatherConfig.IS_UNDERGROUND_WEATHER = false;
+  });
+
+  it("should correctly calculate outside values with negative distance / luminosity", () => {
+    expect(calculateObjectVisibility(MockGameObject.mock(), MockGameObject.mock(), 100, 10, -1, 5, 7, -1, 5, 10)).toBe(
+      -1799.9964000000002
+    );
+    expect(
+      calculateObjectVisibility(MockGameObject.mock(), MockGameObject.mock(), 100, 10, 0.00001, 5, 7, 0.00001, 5, 10)
+    ).toBe(-1799.9964000000002);
+  });
+
+  it("should correctly calculate outside and inside", () => {
+    weatherConfig.IS_UNDERGROUND_WEATHER = false;
+    expect(
+      calculateObjectVisibility(MockGameObject.mock(), MockGameObject.mock(), 100, 10, 1, 5, 7, 150, 100, 10)
+    ).toBe(120);
+    expect(
+      calculateObjectVisibility(MockGameObject.mock(), MockGameObject.mock(), 25.5, 5.5, 10.5, 8.5, 4.5, 2.5, 1.5, 0.5)
+    ).toBe(764.3045454545455);
+
+    weatherConfig.IS_UNDERGROUND_WEATHER = true;
+    expect(
+      calculateObjectVisibility(MockGameObject.mock(), MockGameObject.mock(), 100, 10, 1, 5, 7, 150, 100, 10)
+    ).toBe(42);
+    expect(
+      calculateObjectVisibility(MockGameObject.mock(), MockGameObject.mock(), 25.5, 5.5, 10.5, 8.5, 4.5, 2.5, 1.5, 0.5)
+    ).toBe(267.50659090909096);
+  });
+});
diff --git a/src/engine/core/ai/combat/combat_visibility_calculation.ts b/src/engine/core/ai/combat/combat_visibility_calculation.ts
new file mode 100644
index 000000000..1d57726a2
--- /dev/null
+++ b/src/engine/core/ai/combat/combat_visibility_calculation.ts
@@ -0,0 +1,46 @@
+import { weatherConfig } from "@/engine/core/managers/weather/WeatherConfig";
+import { GameObject, Optional, TDistance, TDuration, TRate } from "@/engine/lib/types";
+
+/**
+ * If value >= visiblity_threshold then object is considered visible.
+ * `visibility_threshold` is configured in LTX files for each monster / stalker separately.
+ *
+ * @param object - target object checking visibility
+ * @param target - target checking visibility for from perspective of object
+ * @param timeDelta - ?
+ * @param timeQuantity - ?
+ * @param luminosity - level of brightness outside
+ * @param velocityFactor - ?
+ * @param velocity - ?
+ * @param distance - ?
+ * @param objectDistance - ?
+ * @param alwaysVisibleDistance -?
+ * @returns visibility rate
+ */
+export function calculateObjectVisibility(
+  object: Optional<GameObject>,
+  target: Optional<GameObject>,
+  timeDelta: TDuration,
+  timeQuantity: TDuration,
+  luminosity: TRate,
+  velocityFactor: TRate,
+  velocity: TRate,
+  distance: TDistance,
+  objectDistance: TDistance,
+  alwaysVisibleDistance: TDistance
+): TRate {
+  luminosity = luminosity <= 0 ? 0.00001 : luminosity;
+  distance = distance <= 0 ? 0.00001 : distance;
+
+  if (weatherConfig.IS_UNDERGROUND_WEATHER) {
+    luminosity *= 0.35;
+  }
+
+  // Unaltered formula from engine:
+  // time_delta / time_quant * luminocity * (1 + velocity_factor*velocity) * (distance - object_distance) /
+  //   (distance - always_visible_distance)
+
+  return (
+    ((timeDelta / timeQuantity) * luminosity * (1 + velocityFactor * velocity) * (distance - objectDistance)) / distance
+  );
+}
diff --git a/src/engine/core/ai/combat/combat_weapon_select.test.ts b/src/engine/core/ai/combat/combat_weapon_select.test.ts
new file mode 100644
index 000000000..651cedaf7
--- /dev/null
+++ b/src/engine/core/ai/combat/combat_weapon_select.test.ts
@@ -0,0 +1,139 @@
+import { beforeEach, describe, expect, it } from "@jest/globals";
+import { clsid } from "xray16";
+
+import { selectBestStalkerWeapon } from "@/engine/core/ai/combat/combat_weapon_select";
+import { getManager, registerSimulator } from "@/engine/core/database";
+import { EGameEvent, EventsManager } from "@/engine/core/managers/events";
+import { AnyObject, GameObject } from "@/engine/lib/types";
+import { resetRegistry } from "@/fixtures/engine";
+import { MockAlifeObject, MockGameObject } from "@/fixtures/xray";
+
+describe("selectBestStalkerWeapon util", () => {
+  beforeEach(() => {
+    resetRegistry();
+    registerSimulator();
+  });
+
+  it("should fallback to null if no handlers found", () => {
+    expect(selectBestStalkerWeapon(MockGameObject.mock(), MockGameObject.mock())).toBeNull();
+    expect(selectBestStalkerWeapon(MockGameObject.mock(), null)).toBeNull();
+  });
+
+  it("should handle exceptional cases from callback handlers without throwing", () => {
+    const eventsManager: EventsManager = getManager(EventsManager);
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        data.weaponId = true;
+      }
+    );
+
+    expect(selectBestStalkerWeapon(MockGameObject.mock(), MockGameObject.mock())).toBeNull();
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        data.weaponId = "test-string";
+      }
+    );
+
+    expect(selectBestStalkerWeapon(MockGameObject.mock(), MockGameObject.mock())).toBeNull();
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        data.weaponId = {};
+      }
+    );
+
+    expect(selectBestStalkerWeapon(MockGameObject.mock(), MockGameObject.mock())).toBeNull();
+  });
+
+  it("should use weapon from latest event handler", () => {
+    const object: GameObject = MockGameObject.mock();
+    const weapon: GameObject = MockGameObject.mock();
+
+    const firstBestWeapon: GameObject = MockGameObject.mock();
+    const secondBestWeapon: GameObject = MockGameObject.mock();
+
+    MockAlifeObject.mock({
+      id: firstBestWeapon.id(),
+      parentId: object.id(),
+      clsid: clsid.wpn_svd,
+    });
+
+    MockAlifeObject.mock({
+      id: secondBestWeapon.id(),
+      parentId: object.id(),
+      clsid: clsid.wpn_ak74,
+    });
+
+    const eventsManager: EventsManager = getManager(EventsManager);
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        expect(data).toEqual({ weaponId: null });
+        data.weaponId = firstBestWeapon.id();
+      }
+    );
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        expect(data).toEqual({ weaponId: firstBestWeapon.id() });
+        data.weaponId = secondBestWeapon.id();
+      }
+    );
+
+    expect(selectBestStalkerWeapon(object, weapon)).toBe(secondBestWeapon);
+  });
+
+  it("should require weapon ownership to use it", () => {
+    const object: GameObject = MockGameObject.mock();
+    const weapon: GameObject = MockGameObject.mock();
+
+    const bestWeapon: GameObject = MockGameObject.mock();
+
+    MockAlifeObject.mock({
+      id: bestWeapon.id(),
+      clsid: clsid.wpn_svd,
+    });
+
+    const eventsManager: EventsManager = getManager(EventsManager);
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        data.weaponId = bestWeapon.id();
+      }
+    );
+
+    expect(selectBestStalkerWeapon(object, weapon)).toBeNull();
+  });
+
+  it("should require weapon cls id to use it", () => {
+    const object: GameObject = MockGameObject.mock();
+    const weapon: GameObject = MockGameObject.mock();
+
+    const bestWeapon: GameObject = MockGameObject.mock();
+
+    MockAlifeObject.mock({
+      id: bestWeapon.id(),
+      parentId: object.id(),
+      clsid: clsid.obj_food,
+    });
+
+    const eventsManager: EventsManager = getManager(EventsManager);
+
+    eventsManager.registerCallback(
+      EGameEvent.STALKER_WEAPON_SELECT,
+      (_: GameObject, __: GameObject, data: AnyObject) => {
+        data.weaponId = bestWeapon.id();
+      }
+    );
+
+    expect(selectBestStalkerWeapon(object, weapon)).toBeNull();
+  });
+});
diff --git a/src/engine/core/ai/combat/combat_weapon_select.ts b/src/engine/core/ai/combat/combat_weapon_select.ts
new file mode 100644
index 000000000..3af212c5f
--- /dev/null
+++ b/src/engine/core/ai/combat/combat_weapon_select.ts
@@ -0,0 +1,41 @@
+import { level } from "xray16";
+
+import { registry } from "@/engine/core/database";
+import { EGameEvent, EventsManager } from "@/engine/core/managers/events";
+import { isWeapon } from "@/engine/core/utils/class_ids";
+import { GameObject, Optional, ServerObject, TNumberId, TStringId } from "@/engine/lib/types";
+
+/**
+ * Try to pick the best weapon to kill enemy based on situation.
+ * Returning null value will delegate choosing of weapon to game engine.
+ *
+ * This method leaves place for weapon custom logics implementation using events / extensions.
+ *
+ * @param object - stalker object to pick the best weapon for
+ * @param weapon - currently selected best weapon to kill enemy
+ * @returns best weapon to use for enemy kill or null
+ */
+export function selectBestStalkerWeapon(object: GameObject, weapon: Optional<GameObject>): Optional<GameObject> {
+  const data = { weaponId: null as Optional<TNumberId | TStringId> };
+
+  EventsManager.emitEvent(EGameEvent.STALKER_WEAPON_SELECT, object, weapon, data);
+
+  if (data.weaponId && typeof data.weaponId === "number") {
+    const nextWeaponId: TNumberId = tonumber(data.weaponId) as TNumberId;
+    const nextWeaponServerObject: Optional<ServerObject> = registry.simulator.object(nextWeaponId);
+
+    if (
+      nextWeaponServerObject &&
+      isWeapon(nextWeaponServerObject) &&
+      nextWeaponServerObject.parent_id === object.id()
+    ) {
+      const gunObject: Optional<GameObject> = level.object_by_id(nextWeaponId);
+
+      if (gunObject) {
+        return gunObject;
+      }
+    }
+  }
+
+  return null;
+}
diff --git a/src/engine/core/ai/combat/index.ts b/src/engine/core/ai/combat/index.ts
new file mode 100644
index 000000000..4ea76cf8b
--- /dev/null
+++ b/src/engine/core/ai/combat/index.ts
@@ -0,0 +1,2 @@
+export * from "@/engine/core/ai/combat/combat_visibility_calculation";
+export * from "@/engine/core/ai/combat/combat_weapon_select";
diff --git a/src/engine/core/binders/creature/ActorBinder.test.ts b/src/engine/core/binders/creature/ActorBinder.test.ts
index 7da487473..3d0a690ab 100644
--- a/src/engine/core/binders/creature/ActorBinder.test.ts
+++ b/src/engine/core/binders/creature/ActorBinder.test.ts
@@ -119,14 +119,15 @@ describe("ActorBinder", () => {
     expect(state).not.toBeNull();
     expect(state.portableStore).not.toBeNull();
 
-    expect(actor.set_callback).toHaveBeenCalledTimes(7);
+    expect(actor.set_callback).toHaveBeenCalledTimes(8);
     expect(actor.set_callback).toHaveBeenCalledWith(callback.inventory_info, expect.any(Function));
+    expect(actor.set_callback).toHaveBeenCalledWith(callback.take_item_from_box, expect.any(Function));
     expect(actor.set_callback).toHaveBeenCalledWith(callback.on_item_take, expect.any(Function));
     expect(actor.set_callback).toHaveBeenCalledWith(callback.on_item_drop, expect.any(Function));
     expect(actor.set_callback).toHaveBeenCalledWith(callback.trade_sell_buy_item, expect.any(Function));
     expect(actor.set_callback).toHaveBeenCalledWith(callback.task_state, expect.any(Function));
-    expect(actor.set_callback).toHaveBeenCalledWith(callback.take_item_from_box, expect.any(Function));
     expect(actor.set_callback).toHaveBeenCalledWith(callback.use_object, expect.any(Function));
+    expect(actor.set_callback).toHaveBeenCalledWith(callback.hud_animation_end, expect.any(Function));
 
     expect(eventsManager.emitEvent).toHaveBeenCalledWith(EGameEvent.ACTOR_REINIT, binder);
   });
diff --git a/src/engine/core/binders/creature/ActorBinder.ts b/src/engine/core/binders/creature/ActorBinder.ts
index 436544e3b..6c4d9c554 100644
--- a/src/engine/core/binders/creature/ActorBinder.ts
+++ b/src/engine/core/binders/creature/ActorBinder.ts
@@ -34,6 +34,8 @@ import {
   ServerActorObject,
   TCount,
   TDuration,
+  TName,
+  TSection,
   TTaskState,
   TTimestamp,
 } from "@/engine/lib/types";
@@ -233,10 +235,14 @@ export class ActorBinder extends object_binder {
     object.set_callback(callback.use_object, (object: GameObject) => {
       eventsManager.emitEvent(EGameEvent.ACTOR_USE_ITEM, object);
     });
+    object.set_callback(callback.hud_animation_end, (object: GameObject, hudSection: TSection, motion: TName) => {
+      logger.info("Hud animation ended: %s - %s - %s", object.name(), hudSection, motion);
+    });
 
     // todo: article_info info callback.
     // todo: level_border_enter info callback.
     // todo: level_border_exit info callback.
+    // todo: before death callback.
   }
 
   /**
diff --git a/src/engine/core/managers/actor/ActorInputManager.test.ts b/src/engine/core/managers/actor/ActorInputManager.test.ts
index fd803582d..0c3ab3923 100644
--- a/src/engine/core/managers/actor/ActorInputManager.test.ts
+++ b/src/engine/core/managers/actor/ActorInputManager.test.ts
@@ -173,7 +173,7 @@ describe("ActorInputManager", () => {
     expect(registry.effectsVolume).toBe(0.8);
   });
 
-  it("should correctly first update event", () => {
+  it("should correctly handle first update event", () => {
     const manager: ActorInputManager = getManager(ActorInputManager);
 
     actorConfig.ACTIVE_ITEM_SLOT = EActiveItemSlot.PRIMARY;
@@ -187,7 +187,7 @@ describe("ActorInputManager", () => {
     expect(registry.actor.activate_slot).toHaveBeenNthCalledWith(2, EActiveItemSlot.KNIFE);
   });
 
-  it("should correctly network spawn event", () => {
+  it("should correctly handle network spawn event", () => {
     const manager: ActorInputManager = getManager(ActorInputManager);
 
     actorConfig.DISABLED_INPUT_AT = MockCTime.mock(2012, 12, 1, 12, 30, 5, 500);
@@ -198,4 +198,10 @@ describe("ActorInputManager", () => {
     manager.onActorGoOnline();
     expect(level.enable_input).toHaveBeenCalledTimes(1);
   });
+
+  it("should correctly handle keyboard input event", () => {
+    const manager: ActorInputManager = getManager(ActorInputManager);
+
+    expect(manager.onKeyPress(1, 2)).toBe(false);
+  });
 });
diff --git a/src/engine/core/managers/actor/ActorInputManager.ts b/src/engine/core/managers/actor/ActorInputManager.ts
index 26109171a..7872c8cba 100644
--- a/src/engine/core/managers/actor/ActorInputManager.ts
+++ b/src/engine/core/managers/actor/ActorInputManager.ts
@@ -34,6 +34,7 @@ import {
   Optional,
   TDuration,
   TIndex,
+  TNumberId,
   TRate,
 } from "@/engine/lib/types";
 
@@ -400,4 +401,25 @@ export class ActorInputManager extends AbstractManager {
   public onSurgeSurviveEnd(): void {
     this.enableGameUi();
   }
+
+  /**
+   * Handle actor keyboard input pressing.
+   *
+   * @param key - key code
+   * @param bind - key binding code
+   * @returns whether action was handled by script and engine should stop further execution of callbacks
+   */
+  public onKeyPress(key: TNumberId, bind: TNumberId): boolean {
+    /**
+     * Place to implement quick save / quick load logics with incremental naming / rotating files.
+     * For reference, check anomaly/CoC etc.
+     *
+     * -> scripts/level_input.script
+     *    on_key_press
+     *    action_quick_save
+     *    action_quick_load
+     */
+
+    return false;
+  }
 }
diff --git a/src/engine/core/managers/actor/ActorInventoryMenuManager.test.ts b/src/engine/core/managers/actor/ActorInventoryMenuManager.test.ts
index 7acd21529..4d715ab3d 100644
--- a/src/engine/core/managers/actor/ActorInventoryMenuManager.test.ts
+++ b/src/engine/core/managers/actor/ActorInventoryMenuManager.test.ts
@@ -90,6 +90,18 @@ describe("ActorInventoryMenuManager", () => {
     expect(manager.onWindowClosed).toHaveBeenCalledWith(EActorMenuMode.TALK_DIALOG);
   });
 
+  it("should correctly handle item focus receive event", () => {
+    expect(() => {
+      getManager(ActorInventoryMenuManager).onItemFocusReceived(MockGameObject.mock());
+    }).not.toThrow();
+  });
+
+  it("should correctly handle item focus lost event", () => {
+    expect(() => {
+      getManager(ActorInventoryMenuManager).onItemFocusLost(MockGameObject.mock());
+    }).not.toThrow();
+  });
+
   it("should correctly handle drop item event", () => {
     expect(() => {
       getManager(ActorInventoryMenuManager).onItemDropped(
diff --git a/src/engine/core/managers/actor/ActorInventoryMenuManager.ts b/src/engine/core/managers/actor/ActorInventoryMenuManager.ts
index 7386a39ab..81866a48a 100644
--- a/src/engine/core/managers/actor/ActorInventoryMenuManager.ts
+++ b/src/engine/core/managers/actor/ActorInventoryMenuManager.ts
@@ -84,6 +84,20 @@ export class ActorInventoryMenuManager extends AbstractManager {
     actorConfig.ACTOR_MENU_MODE = EActorMenuMode.UNDEFINED;
   }
 
+  /**
+   * @param item - item game object receiving UI focus
+   */
+  public onItemFocusReceived(item: GameObject): void {
+    logger.info("Actor item focus received: %s", item?.name());
+  }
+
+  /**
+   * @param item - item game object losing UI focus
+   */
+  public onItemFocusLost(item: GameObject): void {
+    logger.info("Actor item focus lost: %s", item?.name());
+  }
+
   /**
    * @param from - game object owner of previous list
    * @param to - game object owner of next list
diff --git a/src/engine/core/managers/death/ReleaseBodyManager.ts b/src/engine/core/managers/death/ReleaseBodyManager.ts
index 3beecf39b..50576c861 100644
--- a/src/engine/core/managers/death/ReleaseBodyManager.ts
+++ b/src/engine/core/managers/death/ReleaseBodyManager.ts
@@ -23,6 +23,8 @@ const logger: LuaLogger = new LuaLogger($filename);
 /**
  * Manage persisting dead bodies.
  * Release the most further of them from time to time to keep up with limits.
+ *
+ * todo: EGameEvent.BEFORE_LEVEL_CHANGE -> call releaseCorpses?
  */
 export class ReleaseBodyManager extends AbstractManager {
   public override initialize(): void {
diff --git a/src/engine/core/managers/events/EventsManager.test.ts b/src/engine/core/managers/events/EventsManager.test.ts
index e448f13dc..0f72a389d 100644
--- a/src/engine/core/managers/events/EventsManager.test.ts
+++ b/src/engine/core/managers/events/EventsManager.test.ts
@@ -14,7 +14,7 @@ describe("EventsManager", () => {
   it("should correctly initialize", () => {
     const manager: EventsManager = getManager(EventsManager);
 
-    expect(MockLuaTable.getMockSize(manager.callbacks)).toBe(120);
+    expect(MockLuaTable.getMockSize(manager.callbacks)).toBe(125);
 
     Object.keys(manager.callbacks).forEach((it) => {
       expect(MockLuaTable.getMockSize(manager.callbacks[it as unknown as EGameEvent])).toBe(0);
diff --git a/src/engine/core/managers/events/events_types.ts b/src/engine/core/managers/events/events_types.ts
index 0f65dbdfe..477e1332b 100644
--- a/src/engine/core/managers/events/events_types.ts
+++ b/src/engine/core/managers/events/events_types.ts
@@ -126,6 +126,10 @@ export enum EGameEvent {
    * Server side death event.
    */
   STALKER_DEATH_ALIFE,
+  /**
+   * Stalker weapon selection is needed.
+   */
+  STALKER_WEAPON_SELECT,
   /**
    * On monster register.
    */
@@ -424,6 +428,10 @@ export enum EGameEvent {
    * Unregistered shotgun weapon server object.
    */
   ITEM_WEAPON_SHOTGUN_UNREGISTERED,
+  /**
+   * Unregistered generic server ALifeDynamicObject.
+   */
+  SERVER_OBJECT_UNREGISTERED,
   /**
    * Surge ended.
    */
@@ -484,10 +492,22 @@ export enum EGameEvent {
    * Game state save.
    */
   GAME_SAVE,
+  /**
+   * Game state saved.
+   */
+  GAME_SAVED,
   /**
    * Game state load.
    */
   GAME_LOAD,
+  /**
+   * Game state loaded.
+   */
+  GAME_LOADED,
+  /**
+   * Event called before level change.
+   */
+  BEFORE_LEVEL_CHANGE,
 }
 
 /**
diff --git a/src/engine/core/managers/save/SaveManager.test.ts b/src/engine/core/managers/save/SaveManager.test.ts
index fb8ec0e19..bf25d7660 100644
--- a/src/engine/core/managers/save/SaveManager.test.ts
+++ b/src/engine/core/managers/save/SaveManager.test.ts
@@ -23,7 +23,7 @@ import { TaskManager } from "@/engine/core/managers/tasks";
 import { TreasureManager } from "@/engine/core/managers/treasures";
 import { WeatherManager } from "@/engine/core/managers/weather/WeatherManager";
 import { IExtensionsDescriptor } from "@/engine/core/utils/extensions";
-import { AnyObject } from "@/engine/lib/types";
+import { AnyObject, TName } from "@/engine/lib/types";
 import { mockExtension, resetRegistry } from "@/fixtures/engine";
 import { resetFunctionMock } from "@/fixtures/jest";
 import { MockIoFile } from "@/fixtures/lua";
@@ -140,8 +140,8 @@ describe("SaveManager", () => {
 
     expect(saveManager.onBeforeGameSave).toBeDefined();
     expect(saveManager.onGameSave).toBeDefined();
-    expect(saveManager.onBeforeGameLoad).toBeDefined();
     expect(saveManager.onGameLoad).toBeDefined();
+    expect(saveManager.onAfterGameLoad).toBeDefined();
   });
 
   it("should properly create dynamic saves", () => {
@@ -157,7 +157,8 @@ describe("SaveManager", () => {
     registry.extensions.set(firstExtension.name, firstExtension);
     registry.extensions.set(secondExtension.name, secondExtension);
 
-    const onSave = jest.fn((data: AnyObject) => {
+    const onSave = jest.fn((saveName: TName, data: AnyObject) => {
+      expect(saveName).toBe("test.scop");
       data.example = 123;
     });
 
@@ -184,6 +185,19 @@ describe("SaveManager", () => {
     expect(file.close).toHaveBeenCalledTimes(1);
   });
 
+  it("should properly handle after game saved event", () => {
+    const saveManager: SaveManager = getManager(SaveManager);
+
+    const onSaved = jest.fn();
+
+    getManager(EventsManager).registerCallback(EGameEvent.GAME_SAVED, onSaved);
+
+    saveManager.onGameSave("test.scop");
+
+    expect(onSaved).toHaveBeenCalledTimes(1);
+    expect(onSaved).toHaveBeenCalledWith("test.scop");
+  });
+
   it("should properly load dynamic saves", () => {
     const saveManager: SaveManager = getManager(SaveManager);
     const file: MockIoFile = new MockIoFile("test", "wb");
@@ -204,7 +218,8 @@ describe("SaveManager", () => {
       objects: {},
     });
 
-    const onLoad = jest.fn((data: AnyObject) => {
+    const onLoad = jest.fn((saveName: TName, data: AnyObject) => {
+      expect(saveName).toBe("F:\\\\parent\\\\test.scop");
       expect(data).toEqual({ example: 123 });
     });
 
@@ -214,7 +229,7 @@ describe("SaveManager", () => {
 
     const contentBefore: AnyObject = registry.dynamicData;
 
-    saveManager.onBeforeGameLoad("F:\\\\parent\\\\test.scop");
+    saveManager.onGameLoad("F:\\\\parent\\\\test.scop");
 
     expect(marshal.decode).toHaveBeenCalledWith(file.content);
     expect(onLoad).toHaveBeenCalledTimes(1);
@@ -241,16 +256,29 @@ describe("SaveManager", () => {
     const contentAfter: AnyObject = registry.dynamicData;
 
     file.content = "";
-    saveManager.onBeforeGameLoad("F:\\\\parent\\\\test.scop");
+    saveManager.onGameLoad("F:\\\\parent\\\\test.scop");
     expect(contentAfter).toBe(registry.dynamicData);
 
     file.content = null;
-    saveManager.onBeforeGameLoad("F:\\\\parent\\\\test.scop");
+    saveManager.onGameLoad("F:\\\\parent\\\\test.scop");
     expect(contentAfter).toBe(registry.dynamicData);
 
     file.content = "{}";
     file.isOpen = false;
-    saveManager.onBeforeGameLoad("F:\\\\parent\\\\test.scop");
+    saveManager.onGameLoad("F:\\\\parent\\\\test.scop");
     expect(contentAfter).toBe(registry.dynamicData);
   });
+
+  it("should properly handle callback after game loaded", () => {
+    const saveManager: SaveManager = getManager(SaveManager);
+
+    const onLoad = jest.fn();
+
+    getManager(EventsManager).registerCallback(EGameEvent.GAME_LOADED, onLoad);
+
+    saveManager.onAfterGameLoad("F:\\\\parent\\\\test.scop");
+
+    expect(onLoad).toHaveBeenCalledTimes(1);
+    expect(onLoad).toHaveBeenCalledWith("F:\\\\parent\\\\test.scop");
+  });
 });
diff --git a/src/engine/core/managers/save/SaveManager.ts b/src/engine/core/managers/save/SaveManager.ts
index a422be45b..99fa29f28 100644
--- a/src/engine/core/managers/save/SaveManager.ts
+++ b/src/engine/core/managers/save/SaveManager.ts
@@ -97,7 +97,7 @@ export class SaveManager extends AbstractManager {
   public onBeforeGameSave(saveName: TName): void {
     logger.info("Before game save: %s", saveName);
 
-    EventsManager.emitEvent(EGameEvent.GAME_SAVE, registry.dynamicData.event);
+    EventsManager.emitEvent(EGameEvent.GAME_SAVE, saveName, registry.dynamicData.event);
 
     for (const [, extension] of registry.extensions) {
       saveExtension(extension);
@@ -113,15 +113,17 @@ export class SaveManager extends AbstractManager {
    */
   public onGameSave(saveName: TName): void {
     logger.info("On game save: %s", saveName);
+
+    EventsManager.emitEvent(EGameEvent.GAME_SAVED, saveName);
   }
 
   /**
-   * When game save loading starts.
+   * When game loading starts.
    *
    * @param saveName - name of save file, full path with disk/system folders structure
    */
-  public onBeforeGameLoad(saveName: TName): void {
-    logger.info("Before game load: %s", saveName);
+  public onGameLoad(saveName: TName): void {
+    logger.info("On game load: %s", saveName);
 
     registry.dynamicData = loadDynamicGameSave(saveName) ?? registry.dynamicData;
 
@@ -129,16 +131,18 @@ export class SaveManager extends AbstractManager {
       loadExtension(extension);
     }
 
-    EventsManager.emitEvent(EGameEvent.GAME_LOAD, registry.dynamicData.event);
+    EventsManager.emitEvent(EGameEvent.GAME_LOAD, saveName, registry.dynamicData.event);
   }
 
   /**
-   * When game save loaded successfully.
+   * When game loaded successfully.
    *
    * @param saveName - name of save file, full path with disk/system folders structure
    */
-  public onGameLoad(saveName: TName): void {
-    logger.info("On game load: %s", saveName);
+  public onAfterGameLoad(saveName: TName): void {
+    logger.info("On after game load: %s", saveName);
+
+    EventsManager.emitEvent(EGameEvent.GAME_LOADED, saveName);
   }
 
   /**
diff --git a/src/engine/core/managers/simulation/SimulationConfig.ts b/src/engine/core/managers/simulation/SimulationConfig.ts
index 2eef97e03..c8cf99819 100644
--- a/src/engine/core/managers/simulation/SimulationConfig.ts
+++ b/src/engine/core/managers/simulation/SimulationConfig.ts
@@ -12,7 +12,7 @@ export const SIMULATION_OBJECTS_PROPERTIES_LTX: IniFile = new ini_file(
 );
 
 /**
- * todo: Remove / use strings / solve it
+ * todo: Remove / use strings / simplify and make more scalable
  */
 export const GROUP_ID_BY_LEVEL_NAME: LuaTable<TLevel, TNumberId> = $fromObject({
   [levels.zaton]: 1,
diff --git a/src/engine/core/managers/trade/TradeManager.test.ts b/src/engine/core/managers/trade/TradeManager.test.ts
index 09c8d666a..a9ae2edb2 100644
--- a/src/engine/core/managers/trade/TradeManager.test.ts
+++ b/src/engine/core/managers/trade/TradeManager.test.ts
@@ -106,7 +106,7 @@ describe("TradeManager class implementation", () => {
     expect(tradeManager.getBuyDiscountForObject(object.id())).toBe(0.3);
   });
 
-  it("TradeManager should correctly save and load data when not initialized", () => {
+  it("should correctly save and load data when not initialized", () => {
     const tradeManager: TradeManager = getManager(TradeManager);
     const object: GameObject = MockGameObject.mock();
     const processor: MockNetProcessor = new MockNetProcessor();
@@ -127,7 +127,11 @@ describe("TradeManager class implementation", () => {
     expect(registry.trade.get(object.id())).toBeNull();
   });
 
-  it("TradeManager should correctly save and load data when not updated", () => {
+  it("should correctly check if item can be traded (now always true)", () => {
+    expect(getManager(TradeManager).isItemAvailableForTrade(MockGameObject.mock(), MockGameObject.mock())).toBe(true);
+  });
+
+  it("should correctly save and load data when not updated", () => {
     const tradeManager: TradeManager = getManager(TradeManager);
     const object: GameObject = MockGameObject.mock();
     const ini: IniFile = loadIniFile("managers\\trade\\trade_generic.ltx");
@@ -171,7 +175,7 @@ describe("TradeManager class implementation", () => {
     });
   });
 
-  it("TradeManager should correctly save and load data when updated", () => {
+  it("should correctly save and load data when updated", () => {
     const tradeManager: TradeManager = getManager(TradeManager);
     const object: GameObject = MockGameObject.mock();
     const ini: IniFile = loadIniFile("managers\\trade\\trade_generic.ltx");
diff --git a/src/engine/core/managers/trade/TradeManager.ts b/src/engine/core/managers/trade/TradeManager.ts
index ae8d086c7..b9d14f494 100644
--- a/src/engine/core/managers/trade/TradeManager.ts
+++ b/src/engine/core/managers/trade/TradeManager.ts
@@ -192,6 +192,15 @@ export class TradeManager extends AbstractManager {
     }
   }
 
+  /**
+   * @param owner - item owner game object
+   * @param item - target item to check
+   * @returns whether item can be traded (script logics overriding)
+   */
+  public isItemAvailableForTrade(owner: GameObject, item: GameObject): boolean {
+    return true;
+  }
+
   /**
    * Save object state in net processor.
    *
diff --git a/src/engine/core/managers/weather/WeatherConfig.ts b/src/engine/core/managers/weather/WeatherConfig.ts
index fa72d26b0..d1a371485 100644
--- a/src/engine/core/managers/weather/WeatherConfig.ts
+++ b/src/engine/core/managers/weather/WeatherConfig.ts
@@ -23,4 +23,6 @@ export const weatherConfig = {
   // Defines how far fog should be based on time / weather section.
   FOG_DISTANCES: readFogDistances(DYNAMIC_WEATHER_GRAPHS_LTX),
   MONTH_DAYS: $fromArray([31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]),
+  // Whether current weather is considered underground.
+  IS_UNDERGROUND_WEATHER: false,
 };
diff --git a/src/engine/core/managers/weather/WeatherManager.test.ts b/src/engine/core/managers/weather/WeatherManager.test.ts
index 0649407f2..46e93165e 100644
--- a/src/engine/core/managers/weather/WeatherManager.test.ts
+++ b/src/engine/core/managers/weather/WeatherManager.test.ts
@@ -1,9 +1,10 @@
-import { beforeEach, describe, expect, it } from "@jest/globals";
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
 import { level } from "xray16";
 
 import { disposeManager, getManager } from "@/engine/core/database";
 import { EGameEvent, EventsManager } from "@/engine/core/managers/events";
 import { EWeatherPeriodType, IWeatherState } from "@/engine/core/managers/weather/weather_types";
+import { weatherConfig } from "@/engine/core/managers/weather/WeatherConfig";
 import { WeatherManager } from "@/engine/core/managers/weather/WeatherManager";
 import { NIL } from "@/engine/lib/constants/words";
 import { resetRegistry } from "@/fixtures/engine";
@@ -14,6 +15,8 @@ import { EPacketDataType, MockNetProcessor } from "@/fixtures/xray/mocks/save";
 describe("WeatherManager", () => {
   beforeEach(() => {
     resetRegistry();
+
+    weatherConfig.IS_UNDERGROUND_WEATHER = false;
   });
 
   it("should correctly initialize and destroy", () => {
@@ -36,11 +39,20 @@ describe("WeatherManager", () => {
 
     eventsManager.emitEvent(EGameEvent.ACTOR_GO_ONLINE);
 
-    expect(level.name()).toBe("zaton");
+    jest.spyOn(level, "name").mockImplementation(() => "zaton");
 
+    expect(level.name()).toBe("zaton");
+    expect(weatherConfig.IS_UNDERGROUND_WEATHER).toBe(false);
     expect(manager.weatherPeriod).toBe("good");
     expect(manager.weatherSection).toBe("atmosfear_clear_foggy");
     expect(String(getFunctionMock(level.set_weather).mock.calls[0][0]).startsWith("af3_slight_")).toBeTruthy();
+
+    jest.spyOn(level, "name").mockImplementation(() => "jupiter_underground");
+
+    expect(level.name()).toBe("jupiter_underground");
+    expect(weatherConfig.IS_UNDERGROUND_WEATHER).toBe(false);
+
+    jest.spyOn(level, "name").mockImplementation(() => "zaton");
   });
 
   it("should correctly set state", () => {
diff --git a/src/engine/core/managers/weather/WeatherManager.ts b/src/engine/core/managers/weather/WeatherManager.ts
index 5ebfe63d6..7f14fc4e7 100644
--- a/src/engine/core/managers/weather/WeatherManager.ts
+++ b/src/engine/core/managers/weather/WeatherManager.ts
@@ -39,6 +39,7 @@ import {
   readIniString,
   TConditionList,
 } from "@/engine/core/utils/ini";
+import { isUndergroundLevel } from "@/engine/core/utils/level";
 import { LuaLogger } from "@/engine/core/utils/logging";
 import { NIL } from "@/engine/lib/constants/words";
 import {
@@ -353,11 +354,13 @@ export class WeatherManager extends AbstractManager {
    * Detect current level and environment, reset and re-init states.
    */
   protected onActorNetworkSpawn(): void {
-    logger.info("Initialize weather on network spawn");
-
     const levelName: TName = level.name();
     const levelWeather: TName = readIniString(GAME_LTX, levelName, "weathers", false, null, ATMOSFEAR_WEATHER);
 
+    logger.info("Initialize weather on network spawn: %s, %s", levelName, levelWeather);
+
+    weatherConfig.IS_UNDERGROUND_WEATHER = isUndergroundLevel(levelName);
+
     this.weatherSection = levelWeather;
     this.weatherConditionList = parseConditionsList(levelWeather);
 
diff --git a/src/engine/core/objects/creature/Actor.ts b/src/engine/core/objects/creature/Actor.ts
index 7ff4ac252..823f36b59 100644
--- a/src/engine/core/objects/creature/Actor.ts
+++ b/src/engine/core/objects/creature/Actor.ts
@@ -96,7 +96,7 @@ export class Actor extends cse_alife_creature_actor implements ISimulationTarget
   }
 
   /**
-   * Get generic task.
+   * @returns generic simulation task based on current game graph IDs
    */
   public getSimulationTask(): ALifeSmartTerrainTask {
     return new CALifeSmartTerrainTask(this.m_game_vertex_id, this.m_level_vertex_id);
diff --git a/src/engine/core/utils/extensions/extensions_save.ts b/src/engine/core/utils/extensions/extensions_save.ts
index 2c272ce27..5106fb739 100644
--- a/src/engine/core/utils/extensions/extensions_save.ts
+++ b/src/engine/core/utils/extensions/extensions_save.ts
@@ -6,7 +6,10 @@ import { AnyObject } from "@/engine/lib/types";
 const logger: LuaLogger = new LuaLogger($filename);
 
 /**
- * @param extension - description of extension to save data for
+ * Handle save event for provided extension.
+ * Save data in registry dynamic storage for future serialization and storing with lua `marshal` lib.
+ *
+ * @param extension - descriptor of extension to save data for
  */
 export function saveExtension(extension: IExtensionsDescriptor): void {
   if (extension.module.save) {
@@ -21,7 +24,10 @@ export function saveExtension(extension: IExtensionsDescriptor): void {
 }
 
 /**
- * todo
+ * Handle load event for provided extension.
+ * Load data into registry dynamic storage and deserialize it with lua `marshal` lib.
+ *
+ * @param extension - descriptor of extension to load data for
  */
 export function loadExtension(extension: IExtensionsDescriptor): void {
   if (extension.module.load) {
diff --git a/src/engine/core/utils/level.ts b/src/engine/core/utils/level.ts
index 5b568e8e8..2498b7652 100644
--- a/src/engine/core/utils/level.ts
+++ b/src/engine/core/utils/level.ts
@@ -1,14 +1,14 @@
 import { surgeConfig } from "@/engine/core/managers/surge/SurgeConfig";
-import { TLevel } from "@/engine/lib/constants/levels";
+import { TName } from "@/engine/lib/types";
 
 /**
  * Check whether level is underground.
  *
- * todo: Define flag in ltx files for all levels.
+ * todo: Define flag in ltx files for all levels with boolean value, avoid calculations and enums.
  *
  * @param levelName - level name to check
  * @returns whether level is fully indoor.
  */
-export function isUndergroundLevel(levelName: TLevel): boolean {
+export function isUndergroundLevel(levelName: TName): boolean {
   return surgeConfig.UNDERGROUND_LEVELS.get(levelName) === true;
 }
diff --git a/src/engine/lib/constants/console_commands.ts b/src/engine/lib/constants/console_commands.ts
index 575e522d6..ee42d3545 100644
--- a/src/engine/lib/constants/console_commands.ts
+++ b/src/engine/lib/constants/console_commands.ts
@@ -92,6 +92,7 @@
  * CMD3(CCC_Mask, "lua_debug", &g_LuaDebug, 1);
  * CMD3(CCC_Mask, "g_god", &psActorFlags, AF_GODMODE);
  * CMD3(CCC_Mask, "g_unlimitedammo", &psActorFlags, AF_UNLIMITEDAMMO);
+ * CMD3(CCC_Mask, "g_use_tracers", &psActorFlags, AF_USE_TRACERS);
  * CMD4(CCC_TimeFactorSingle, "time_factor_single", &g_fTimeFactor, 0.f, 1000.0f);
  * CMD4(CCC_Vector3, "psp_cam_offset", &CCameraLook2::m_cam_offset, Fvector().set(-1000, -1000, -1000),
  * CMD4(CCC_Float, "ai_smart_factor", &g_smart_cover_factor, 0.f, 1000000.f);
diff --git a/src/engine/lib/constants/sections.ts b/src/engine/lib/constants/sections.ts
index 33eaaa0af..59d7f5223 100644
--- a/src/engine/lib/constants/sections.ts
+++ b/src/engine/lib/constants/sections.ts
@@ -6,7 +6,7 @@ import { TName } from "@/engine/lib/types";
 export const SMART_TERRAIN_SECTION: TName = "smart_terrain";
 
 /**
- * Section representing stalkers that are used only for cutscenes / scenarios (todo: confirm).
+ * Section representing stalkers that are used only for cutscenes / scenarios.
  */
 export const ACTOR_VISUAL_STALKER: TName = "actor_visual_stalker";
 
diff --git a/src/engine/lib/types/scheme.ts b/src/engine/lib/types/scheme.ts
index 475383632..3a20a42fc 100644
--- a/src/engine/lib/types/scheme.ts
+++ b/src/engine/lib/types/scheme.ts
@@ -146,8 +146,6 @@ export enum ESchemeEvent {
  */
 export interface ISchemeEventHandler {
   /**
-   * todo: Swap params order.
-   *
    * Handle schema activation event.
    *
    * @param object - game object activation happen for
diff --git a/src/engine/scripts/declarations/callbacks/game.test.ts b/src/engine/scripts/declarations/callbacks/game.test.ts
index 9c14b7b0d..b51795e05 100644
--- a/src/engine/scripts/declarations/callbacks/game.test.ts
+++ b/src/engine/scripts/declarations/callbacks/game.test.ts
@@ -1,20 +1,18 @@
 import { beforeAll, beforeEach, describe, expect, it, jest } from "@jest/globals";
 
+import { calculateObjectVisibility, selectBestStalkerWeapon } from "@/engine/core/ai/combat";
 import { smartCoversList } from "@/engine/core/animation/smart_covers";
 import { getManager } from "@/engine/core/database";
+import { ActorInputManager } from "@/engine/core/managers/actor";
+import { EGameEvent, EventsManager } from "@/engine/core/managers/events";
 import { gameOutroConfig, GameOutroManager } from "@/engine/core/managers/outro";
 import { SaveManager } from "@/engine/core/managers/save";
 import { TradeManager } from "@/engine/core/managers/trade";
-import { AnyArgs, AnyObject, TName } from "@/engine/lib/types";
-import { callBinding, checkBinding, checkNestedBinding, resetRegistry } from "@/fixtures/engine";
+import { AnyObject, GameObject, NetPacket } from "@/engine/lib/types";
+import { callBinding, callNestedBinding, checkBinding, checkNestedBinding, resetRegistry } from "@/fixtures/engine";
+import { MockGameObject, MockNetProcessor } from "@/fixtures/xray";
 
-function callTradeBinding(name: TName, args: AnyArgs = []): unknown {
-  return callBinding(name, args, (_G as AnyObject)["trade_manager"]);
-}
-
-function callOutroBinding(name: TName, args: AnyArgs = []): void {
-  return callBinding(name, args, (_G as AnyObject)["outro"]);
-}
+jest.mock("@/engine/core/ai/combat");
 
 describe("game external callbacks", () => {
   beforeAll(() => {
@@ -27,16 +25,69 @@ describe("game external callbacks", () => {
 
   it("should correctly inject external methods for game", () => {
     checkBinding("main");
+
+    checkBinding("CSE_ALifeDynamicObject_on_unregister");
+    checkBinding("CALifeUpdateManager__on_before_change_level");
+
     checkBinding("smart_covers");
     checkNestedBinding("smart_covers", "descriptions");
+
     checkBinding("outro");
+    checkNestedBinding("outro", "conditions");
+    checkNestedBinding("outro", "start_bk_sound");
+    checkNestedBinding("outro", "stop_bk_sound");
+    checkNestedBinding("outro", "update_bk_sound_fade_start");
+    checkNestedBinding("outro", "update_bk_sound_fade_stop");
+
     checkBinding("trade_manager");
+    checkNestedBinding("trade_manager", "get_sell_discount");
+    checkNestedBinding("trade_manager", "get_buy_discount");
+
+    checkBinding("alife_storage_manager");
+    checkNestedBinding("alife_storage_manager", "CALifeStorageManager_load");
+    checkNestedBinding("alife_storage_manager", "CALifeStorageManager_after_load");
+    checkNestedBinding("alife_storage_manager", "CALifeStorageManager_before_save");
+    checkNestedBinding("alife_storage_manager", "CALifeStorageManager_save");
+
+    checkBinding("level_input");
+    checkNestedBinding("level_input", "on_key_press");
+
+    checkBinding("visual_memory_manager");
+    checkNestedBinding("visual_memory_manager", "get_visible_value");
+
+    checkBinding("ai_stalker");
+    checkNestedBinding("ai_stalker", "update_best_weapon");
   });
 
   it("main to be defined for custom scripts", () => {
     expect(() => callBinding("main")).not.toThrow();
   });
 
+  it("CSE_ALifeDynamicObject_on_unregister to be defined and emit events", () => {
+    const manager: EventsManager = getManager(EventsManager);
+
+    const onUnregister = jest.fn();
+
+    manager.registerCallback(EGameEvent.SERVER_OBJECT_UNREGISTERED, onUnregister);
+
+    expect(() => callBinding("CSE_ALifeDynamicObject_on_unregister", [5_000])).not.toThrow();
+    expect(onUnregister).toHaveBeenCalledTimes(1);
+    expect(onUnregister).toHaveBeenCalledWith(5_000);
+  });
+
+  it("CALifeUpdateManager__on_before_change_level to be defined and emit events", () => {
+    const manager: EventsManager = getManager(EventsManager);
+    const packet: NetPacket = MockNetProcessor.mockNetPacket();
+
+    const onBeforeLevelChange = jest.fn();
+
+    manager.registerCallback(EGameEvent.BEFORE_LEVEL_CHANGE, onBeforeLevelChange);
+
+    expect(() => callBinding("CALifeUpdateManager__on_before_change_level", [packet])).not.toThrow();
+    expect(onBeforeLevelChange).toHaveBeenCalledTimes(1);
+    expect(onBeforeLevelChange).toHaveBeenCalledWith(packet);
+  });
+
   it("smart_covers should be defined", () => {
     expect((_G as AnyObject).smart_covers.descriptions).toBe(smartCoversList);
   });
@@ -51,17 +102,17 @@ describe("game external callbacks", () => {
 
     expect((_G as AnyObject)["outro"]["conditions"]).toBe(gameOutroConfig.OUTRO_CONDITIONS);
 
-    callOutroBinding("start_bk_sound");
+    callNestedBinding("outro", "start_bk_sound");
     expect(outroManager.startBlackScreenAndSound).toHaveBeenCalled();
 
-    callOutroBinding("stop_bk_sound");
+    callNestedBinding("outro", "stop_bk_sound");
     expect(outroManager.stopBlackScreenAndSound).toHaveBeenCalled();
 
-    callOutroBinding("update_bk_sound_fade_start", [25]);
+    callNestedBinding("outro", "update_bk_sound_fade_start", [25]);
     expect(outroManager.updateBlackScreenAndSoundFadeStart).toHaveBeenCalledWith(25);
     expect(outroManager.stopBlackScreenAndSound).toHaveBeenCalled();
 
-    callOutroBinding("update_bk_sound_fade_stop", [35]);
+    callNestedBinding("outro", "update_bk_sound_fade_stop", [35]);
     expect(outroManager.updateBlackScreenAndSoundFadeStop).toHaveBeenCalledWith(35);
   });
 
@@ -71,46 +122,62 @@ describe("game external callbacks", () => {
     jest.spyOn(tradeManager, "getSellDiscountForObject").mockImplementation(() => 10);
     jest.spyOn(tradeManager, "getBuyDiscountForObject").mockImplementation(() => 20);
 
-    expect(callTradeBinding("get_sell_discount", [30])).toBe(10);
+    expect(callNestedBinding("trade_manager", "get_sell_discount", [30])).toBe(10);
     expect(tradeManager.getSellDiscountForObject).toHaveBeenCalledWith(30);
 
-    expect(callTradeBinding("get_buy_discount", [40])).toBe(20);
+    expect(callNestedBinding("trade_manager", "get_buy_discount", [40])).toBe(20);
     expect(tradeManager.getBuyDiscountForObject).toHaveBeenCalledWith(40);
   });
 
-  it("on_before_game_save should be handled", () => {
+  it("alife storage save methods should be defined", () => {
     const saveManager: SaveManager = getManager(SaveManager);
 
     jest.spyOn(saveManager, "onBeforeGameSave");
+    jest.spyOn(saveManager, "onGameSave");
+    jest.spyOn(saveManager, "onGameLoad");
+    jest.spyOn(saveManager, "onAfterGameLoad");
+
+    callNestedBinding("alife_storage_manager", "CALifeStorageManager_before_save", ["name1"]);
+    expect(saveManager.onBeforeGameSave).toHaveBeenCalledWith("name1");
+
+    callNestedBinding("alife_storage_manager", "CALifeStorageManager_save", ["name2"]);
+    expect(saveManager.onGameSave).toHaveBeenCalledWith("name2");
 
-    callBinding("on_before_game_save", ["name"]);
-    expect(saveManager.onBeforeGameSave).toHaveBeenCalledWith("name");
+    callNestedBinding("alife_storage_manager", "CALifeStorageManager_load", ["name3"]);
+    expect(saveManager.onGameLoad).toHaveBeenCalledWith("name3");
+
+    callNestedBinding("alife_storage_manager", "CALifeStorageManager_after_load", ["name4"]);
+    expect(saveManager.onAfterGameLoad).toHaveBeenCalledWith("name4");
   });
 
-  it("on_game_save should be handled", () => {
-    const saveManager: SaveManager = getManager(SaveManager);
+  it("level_input callbacks should be defined", () => {
+    const manager: ActorInputManager = getManager(ActorInputManager);
 
-    jest.spyOn(saveManager, "onGameSave");
+    jest.spyOn(manager, "onKeyPress").mockImplementation(jest.fn(() => false));
+
+    callNestedBinding("level_input", "on_key_press", [1, 2]);
 
-    callBinding("on_game_save", ["name"]);
-    expect(saveManager.onGameSave).toHaveBeenCalledWith("name");
+    expect(manager.onKeyPress).toHaveBeenCalledTimes(1);
+    expect(manager.onKeyPress).toHaveBeenCalledWith(1, 2);
   });
 
-  it("on_before_game_load should be handled", () => {
-    const saveManager: SaveManager = getManager(SaveManager);
+  it("visual_memory_manager callbacks should be defined", () => {
+    const object: GameObject = MockGameObject.mock();
+    const target: GameObject = MockGameObject.mock();
 
-    jest.spyOn(saveManager, "onBeforeGameLoad");
+    callNestedBinding("visual_memory_manager", "get_visible_value", [object, target, 1000, 50, 25, 5, 1, 200, 20, 2]);
 
-    callBinding("on_before_game_load", ["name"]);
-    expect(saveManager.onBeforeGameLoad).toHaveBeenCalledWith("name");
+    expect(calculateObjectVisibility).toHaveBeenCalledTimes(1);
+    expect(calculateObjectVisibility).toHaveBeenCalledWith(object, target, 1000, 50, 25, 5, 1, 200, 20, 2);
   });
 
-  it("on_game_load should be handled", () => {
-    const saveManager: SaveManager = getManager(SaveManager);
+  it("ai_stalker callbacks should be defined", () => {
+    const object: GameObject = MockGameObject.mock();
+    const weapon: GameObject = MockGameObject.mock();
 
-    jest.spyOn(saveManager, "onGameLoad");
+    callNestedBinding("ai_stalker", "update_best_weapon", [object, weapon]);
 
-    callBinding("on_game_load", ["name"]);
-    expect(saveManager.onGameLoad).toHaveBeenCalledWith("name");
+    expect(selectBestStalkerWeapon).toHaveBeenCalledTimes(1);
+    expect(selectBestStalkerWeapon).toHaveBeenCalledWith(object, weapon);
   });
 });
diff --git a/src/engine/scripts/declarations/callbacks/game.ts b/src/engine/scripts/declarations/callbacks/game.ts
index 8834aa105..924ea972b 100644
--- a/src/engine/scripts/declarations/callbacks/game.ts
+++ b/src/engine/scripts/declarations/callbacks/game.ts
@@ -1,12 +1,15 @@
+import { calculateObjectVisibility, selectBestStalkerWeapon } from "@/engine/core/ai/combat";
 import { smartCoversList } from "@/engine/core/animation/smart_covers";
 import { getManager } from "@/engine/core/database";
+import { ActorInputManager } from "@/engine/core/managers/actor";
+import { EGameEvent, EventsManager } from "@/engine/core/managers/events";
 import { GameOutroManager } from "@/engine/core/managers/outro";
 import { gameOutroConfig } from "@/engine/core/managers/outro/GameOutroConfig";
 import { SaveManager } from "@/engine/core/managers/save";
 import { TradeManager } from "@/engine/core/managers/trade";
 import { extern } from "@/engine/core/utils/binding";
 import { LuaLogger } from "@/engine/core/utils/logging";
-import { TName, TNumberId } from "@/engine/lib/types";
+import { NetPacket, TName, TNumberId } from "@/engine/lib/types";
 
 const logger: LuaLogger = new LuaLogger($filename);
 
@@ -18,6 +21,24 @@ logger.info("Resolve and bind game externals");
  */
 extern("main", () => {});
 
+/**
+ * Declare method for all dynamic objects unregister event.
+ * Good place to remove ids from persistent tables and clean up all object data.
+ */
+extern("CSE_ALifeDynamicObject_on_unregister", (id: TNumberId) => {
+  EventsManager.emitEvent(EGameEvent.SERVER_OBJECT_UNREGISTERED, id);
+});
+
+/**
+ * Handle event before level change.
+ * As an idea - clear corpses or other cleanup logics parts.
+ */
+extern("CALifeUpdateManager__on_before_change_level", (packet: NetPacket) => {
+  logger.info("On before level change callback");
+
+  EventsManager.emitEvent(EGameEvent.BEFORE_LEVEL_CHANGE, packet);
+});
+
 /**
  * Declare list of available smart covers for game engine.
  * Xray uses it internally.
@@ -48,21 +69,48 @@ extern("trade_manager", {
 });
 
 /**
- * Called from game engine just before creating game save.
+ * AlifeStorage callbacks module.
+ * Includes methods working with game saves to provide alternatives for storage packets.
+ * Alternative variants are:
+ *  - Flexible, not hardcoded, can contain extensive data
+ *  - Not limited by game save file upper limits
  */
-extern("on_before_game_save", (saveName: TName) => getManager(SaveManager).onBeforeGameSave(saveName));
+extern("alife_storage_manager", {
+  /**
+   * Called from game engine on loading game save.
+   */
+  CALifeStorageManager_load: (saveName: TName) => getManager(SaveManager).onGameLoad(saveName),
+  /**
+   * Called from game engine after successful game load.
+   */
+  CALifeStorageManager_after_load: (saveName: TName) => getManager(SaveManager).onAfterGameLoad(saveName),
+  /**
+   * Called from game engine just before creating game save.
+   */
+  CALifeStorageManager_before_save: (saveName: TName) => getManager(SaveManager).onBeforeGameSave(saveName),
+  /**
+   * Called from game engine when game save is created.
+   */
+  CALifeStorageManager_save: (saveName: TName) => getManager(SaveManager).onGameSave(saveName),
+});
 
 /**
- * Called from game engine when game save is created.
+ * Callbacks related to game input from player.
  */
-extern("on_game_save", (saveName: TName) => getManager(SaveManager).onGameSave(saveName));
+extern("level_input", {
+  on_key_press: (key: TNumberId, bind: TNumberId) => getManager(ActorInputManager).onKeyPress(key, bind),
+});
 
 /**
- * Called from game engine just before loading game save.
+ * Callbacks related to objects visibility and memory calculation for AI logics execution.
  */
-extern("on_before_game_load", (saveName: TName) => getManager(SaveManager).onBeforeGameLoad(saveName));
+extern("visual_memory_manager", {
+  get_visible_value: calculateObjectVisibility,
+});
 
 /**
- * Called from game engine after loading game save.
+ * Callbacks related to objects AI logics calculation and execution.
  */
-extern("on_game_load", (saveName: TName) => getManager(SaveManager).onGameLoad(saveName));
+extern("ai_stalker", {
+  update_best_weapon: selectBestStalkerWeapon,
+});
diff --git a/src/engine/scripts/declarations/callbacks/interface.test.ts b/src/engine/scripts/declarations/callbacks/interface.test.ts
index 659fea42e..0a5dbb135 100644
--- a/src/engine/scripts/declarations/callbacks/interface.test.ts
+++ b/src/engine/scripts/declarations/callbacks/interface.test.ts
@@ -4,6 +4,7 @@ import { getManager } from "@/engine/core/database";
 import { ActorInventoryMenuManager } from "@/engine/core/managers/actor";
 import { LoadScreenManager } from "@/engine/core/managers/interface/LoadScreenManager";
 import { PdaManager } from "@/engine/core/managers/pda";
+import { TradeManager } from "@/engine/core/managers/trade";
 import {
   canRepairItem,
   getRepairItemAskReplicLabel,
@@ -176,8 +177,16 @@ describe("interface external callbacks", () => {
 
   it("actor_menu_inventory callbacks", () => {
     const actorInventoryMenuManager: ActorInventoryMenuManager = getManager(ActorInventoryMenuManager);
+    const tradeManager: TradeManager = getManager(TradeManager);
 
     jest.spyOn(actorInventoryMenuManager, "onItemDropped").mockImplementation(jest.fn());
+    jest.spyOn(actorInventoryMenuManager, "onItemFocusReceived").mockImplementation(jest.fn());
+    jest.spyOn(actorInventoryMenuManager, "onItemFocusLost").mockImplementation(jest.fn());
+
+    jest.spyOn(tradeManager, "isItemAvailableForTrade").mockImplementation(jest.fn(() => false));
+
+    const owner: GameObject = MockGameObject.mock();
+    const item: GameObject = MockGameObject.mock();
 
     const from: GameObject = MockGameObject.mock();
     const to: GameObject = MockGameObject.mock();
@@ -186,6 +195,16 @@ describe("interface external callbacks", () => {
 
     callBinding("CUIActorMenu_OnItemDropped", [from, to, oldList, newList], (_G as AnyObject)["actor_menu_inventory"]);
     expect(actorInventoryMenuManager.onItemDropped).toHaveBeenCalledWith(from, to, oldList, newList);
+
+    callBinding("CUIActorMenu_OnItemFocusLost", [item], (_G as AnyObject)["actor_menu_inventory"]);
+    expect(actorInventoryMenuManager.onItemFocusLost).toHaveBeenCalledWith(item);
+
+    callBinding("CUIActorMenu_OnItemFocusReceive", [item], (_G as AnyObject)["actor_menu_inventory"]);
+    expect(actorInventoryMenuManager.onItemFocusReceived).toHaveBeenCalledWith(item);
+
+    callBinding("CInventory_ItemAvailableToTrade", [owner, item], (_G as AnyObject)["actor_menu_inventory"]);
+    expect(tradeManager.isItemAvailableForTrade).toHaveBeenCalledWith(owner, item);
+    expect(tradeManager.isItemAvailableForTrade).toHaveReturnedWith(false);
   });
 
   it("pda callbacks", () => {
diff --git a/src/engine/scripts/declarations/callbacks/interface.ts b/src/engine/scripts/declarations/callbacks/interface.ts
index 0e971638a..b6794a515 100644
--- a/src/engine/scripts/declarations/callbacks/interface.ts
+++ b/src/engine/scripts/declarations/callbacks/interface.ts
@@ -2,6 +2,7 @@ import { getManager } from "@/engine/core/database";
 import { ActorInventoryMenuManager } from "@/engine/core/managers/actor/ActorInventoryMenuManager";
 import { LoadScreenManager } from "@/engine/core/managers/interface/LoadScreenManager";
 import { PdaManager } from "@/engine/core/managers/pda/PdaManager";
+import { TradeManager } from "@/engine/core/managers/trade";
 import { UpgradesManager } from "@/engine/core/managers/upgrades/UpgradesManager";
 import {
   getRepairItemAskReplicLabel,
@@ -29,6 +30,7 @@ import {
   TLabel,
   TName,
   TNotCastedBoolean,
+  TNumberId,
   TRate,
   TSection,
 } from "@/engine/lib/types";
@@ -46,7 +48,7 @@ extern("loadscreen", {
 });
 
 /**
- * Handle item upgrade callbacks from game engine.
+ * Item upgrade callbacks from game engine.
  */
 extern("inventory_upgrades", {
   get_upgrade_cost: (section: TSection): TLabel => getUpgradeCostLabel(section),
@@ -71,7 +73,7 @@ extern("inventory_upgrades", {
 });
 
 /**
- * Handle actor menu modes switching (pda, map, inventory).
+ * Actor menu modes switching (pda, map, inventory) callbacks declaration.
  */
 extern("actor_menu", {
   actor_menu_mode: (mode: EActorMenuMode): void => {
@@ -80,7 +82,7 @@ extern("actor_menu", {
 });
 
 /**
- * Handle actor menu callbacks.
+ * Actor menu callbacks declaration.
  */
 extern("actor_menu_inventory", {
   /**
@@ -102,14 +104,32 @@ extern("actor_menu_inventory", {
 
     return true;
   },
+  /**
+   * @param item - item game object receiving focus
+   */
+  CUIActorMenu_OnItemFocusReceive: (item: GameObject) =>
+    getManager(ActorInventoryMenuManager).onItemFocusReceived(item),
+  /**
+   * @param item - item game object losing focus
+   */
+  CUIActorMenu_OnItemFocusLost: (item: GameObject) => getManager(ActorInventoryMenuManager).onItemFocusLost(item),
+  /**
+   * Script utils for logics extending to override availability of some items in NPC trading.
+   *
+   * @param owner - item owning game object
+   * @param item - item game object for check
+   * @returns whether item is available for trading
+   */
+  CInventory_ItemAvailableToTrade: (owner: GameObject, item: GameObject): boolean =>
+    getManager(TradeManager).isItemAvailableForTrade(owner, item),
 });
 
 /**
  * PDA callbacks.
  */
 extern("pda", {
-  set_active_subdialog: (...args: AnyArgs): void => {
-    logger.info("Set active subdialog");
+  set_active_subdialog: (section: TSection): void => {
+    logger.info("Set active sub-dialog: %s", section);
   },
   get_max_resource: (): TCount => {
     return 10;
@@ -120,16 +140,16 @@ extern("pda", {
   get_max_member_count: (): TCount => {
     return 10;
   },
-  actor_menu_mode: (...args: AnyArgs): void => {
-    logger.info("Pda actor menu mode changed");
+  actor_menu_mode: (mode: TNumberId): void => {
+    logger.info("PDA actor menu mode changed: %s", mode);
   },
   // todo: m_UIPropertiesBox, m_cur_location
   property_box_clicked: (...args: AnyArgs): void => {
-    logger.info("Pda box property clicked");
+    logger.info("PDA box property clicked");
   },
   // todo: m_UIPropertiesBox, m_cur_location->ObjectID(), (LPCSTR)m_cur_location->GetLevelName().c_str(), m_cur_location
   property_box_add_properties: (...args: AnyArgs): void => {
-    logger.info("Pda box property added");
+    logger.info("PDA box property added");
   },
   fill_fraction_state: (state: AnyObject): void => {
     getManager(PdaManager).fillFactionState(state);
@@ -149,7 +169,7 @@ extern("pda", {
 });
 
 /**
- * Params in weapon menu in inventory.
+ * Params calculation for weapon menu in inventory.
  */
 extern("ui_wpn_params", {
   GetRPM: (section: TSection, upgradeSections: string): number => readWeaponRPM(section, upgradeSections),
diff --git a/src/fixtures/engine/utils/check_binding.ts b/src/fixtures/engine/utils/check_binding.ts
index 335945297..48a450a0d 100644
--- a/src/fixtures/engine/utils/check_binding.ts
+++ b/src/fixtures/engine/utils/check_binding.ts
@@ -26,6 +26,21 @@ export function callBinding<T>(name: TName, args: AnyArgs = [], container: AnyOb
   return (container[name] as AnyCallable)(...args) as T;
 }
 
+/**
+ * Call nested binding function.
+ *
+ * @param base - base name of global binding object
+ * @param name - name of nested binding
+ * @param args - variadic list of arguments
+ * @param container - container object
+ * @returns generic value from binding function
+ */
+export function callNestedBinding<T>(base: TName, name: TName, args: AnyArgs = [], container: AnyObject = _G): T {
+  checkNestedBinding(base, name, container);
+
+  return (container[base][name] as AnyCallable)(...args) as T;
+}
+
 /**
  * Expect binding to be defined in nested global container.
  *