diff --git a/R/borel.r b/R/borel.r
index c1a44065..43125f07 100644
--- a/R/borel.r
+++ b/R/borel.r
@@ -39,7 +39,7 @@ rborel <- function(n, mu, infinite = Inf) {
   )
   # Run simulations
   simulate_summary(
-    nchains = n,
+    ntrees = n,
     offspring_dist = "pois",
     statistic = "size",
     stat_max = infinite,
diff --git a/R/checks.R b/R/checks.R
index e43f3910..5625922a 100644
--- a/R/checks.R
+++ b/R/checks.R
@@ -58,13 +58,13 @@ check_serial_valid <- function(serials_dist) {
 }
 
 
-#' Check that nchains is greater than 0 and not infinity
+#' Check that `ntrees` is greater than 0 and not infinity
 #'
-#' @param nchains Number of chains to simulate.
+#' @param ntrees Number of trees to simulate.
 #'
 #' @keywords internal
-check_nchains_valid <- function(nchains) {
-  if (!checkmate::test_count(nchains, positive = TRUE)) {
-    stop("`nchains` must be > 0 but less than `Inf`")
+check_ntrees_valid <- function(ntrees) {
+  if (!checkmate::test_count(ntrees, positive = TRUE)) {
+    stop("`ntrees` must be > 0 but less than `Inf`")
   }
 }
diff --git a/R/epichains.R b/R/epichains.R
index 269f83f8..3919dcf2 100644
--- a/R/epichains.R
+++ b/R/epichains.R
@@ -255,7 +255,7 @@ tail.epichains <- function(x, ...) {
 #' @examples
 #' set.seed(123)
 #' chains <- simulate_tree(
-#'   nchains = 10,
+#'   ntrees = 10,
 #'   statistic = "size",
 #'   offspring_dist = "pois",
 #'   stat_max = 10,
diff --git a/R/simulate.r b/R/simulate.r
index ad969219..22af4b0f 100644
--- a/R/simulate.r
+++ b/R/simulate.r
@@ -1,6 +1,6 @@
 #' Simulate transmission trees from an initial number of infections
 #'
-#' @param nchains Number of chains to simulate.
+#' @param ntrees Number of trees to simulate.
 #' @param offspring_dist Offspring distribution: a character string
 #' corresponding to the R distribution function (e.g., "pois" for Poisson,
 #' where \code{\link{rpois}} is the R function to generate Poisson random
@@ -20,7 +20,7 @@
 #' called `n`, that returns a numeric vector of `n` randomly sampled serial
 #' intervals. See details.
 #' @param t0 Start time (if serial interval is given); either a single value
-#' or a vector of same length as `nchains` (number of simulations) with
+#' or a vector of same length as `ntrees` (number of simulations) with
 #' initial times. Defaults to 0.
 #' @param tf End time (if serial interval is given).
 #' @param ... Parameters of the offspring distribution as required by R.
@@ -91,7 +91,7 @@
 #' @examples
 #' set.seed(123)
 #' chains <- simulate_tree(
-#'   nchains = 10,
+#'   ntrees = 10,
 #'   statistic = "size",
 #'   offspring_dist = "pois",
 #'   stat_max = 10,
@@ -112,14 +112,14 @@
 #' Jacob C. (2010). Branching processes: their role in epidemiology.
 #' International journal of environmental research and public health, 7(3),
 #' 1186–1204. \doi{https://doi.org/10.3390/ijerph7031204}
-simulate_tree <- function(nchains, statistic = c("size", "length"),
+simulate_tree <- function(ntrees, statistic = c("size", "length"),
                           offspring_dist, stat_max = Inf,
                           serials_dist, t0 = 0,
                           tf = Inf, ...) {
   statistic <- match.arg(statistic)
 
   # Input checking
-  check_nchains_valid(nchains = nchains)
+  check_ntrees_valid(ntrees = ntrees)
   checkmate::assert_character(statistic)
 
   # check that offspring is properly specified
@@ -153,15 +153,15 @@ simulate_tree <- function(nchains, statistic = c("size", "length"),
   }
 
   # Initialisations
-  stat_track <- rep(1, nchains) # track length or size (depending on `statistic`) #nolint
-  n_offspring <- rep(1, nchains) # current number of offspring
-  sim <- seq_len(nchains) # track chains that are still being simulated
-  ancestor_ids <- rep(1, nchains) # all chains start in generation 1
+  stat_track <- rep(1, ntrees) # track length or size (depending on `statistic`) #nolint
+  n_offspring <- rep(1, ntrees) # current number of offspring
+  sim <- seq_len(ntrees) # track chains that are still being simulated
+  ancestor_ids <- rep(1, ntrees) # all chains start in generation 1
 
   # initialise data frame to hold the transmission trees
   generation <- 1L
   tree_df <- data.frame(
-    chain_id = seq_len(nchains),
+    chain_id = seq_len(ntrees),
     sim_id = 1L,
     ancestor = NA_integer_,
     generation = generation
@@ -190,7 +190,7 @@ simulate_tree <- function(nchains, statistic = c("size", "length"),
     indices <- rep(sim, n_offspring[sim])
 
     # initialise placeholder for the number of offspring
-    n_offspring <- rep(0, nchains)
+    n_offspring <- rep(0, ntrees)
     # assign offspring sum to indices still being simulated
     n_offspring[sim] <- tapply(next_gen, indices, sum)
 
@@ -257,7 +257,7 @@ simulate_tree <- function(nchains, statistic = c("size", "length"),
 
   structure(
     tree_df,
-    chains = nchains,
+    chains = ntrees,
     chain_type = "chains_tree",
     rownames = NULL,
     track_pop = FALSE,
@@ -282,20 +282,20 @@ simulate_tree <- function(nchains, statistic = c("size", "length"),
 #'   susceptible or partially immune population.
 #' @examples
 #' simulate_summary(
-#'   nchains = 10,
+#'   ntrees = 10,
 #'   statistic = "size",
 #'   offspring_dist = "pois",
 #'   stat_max = 10,
 #'   lambda = 2
 #' )
 #' @export
-simulate_summary <- function(nchains, statistic = c("size", "length"),
+simulate_summary <- function(ntrees, statistic = c("size", "length"),
                              offspring_dist,
                              stat_max = Inf, ...) {
   statistic <- match.arg(statistic)
 
   # Input checking
-  check_nchains_valid(nchains = nchains)
+  check_ntrees_valid(ntrees = ntrees)
   checkmate::assert_character(statistic)
 
   # check that offspring is properly specified
@@ -313,11 +313,11 @@ simulate_summary <- function(nchains, statistic = c("size", "length"),
   pars <- list(...)
 
   # Initialisations
-  stat_track <- rep(1, nchains) ## track length or size (depending on `stat`)
-  n_offspring <- rep(1, nchains) ## current number of offspring
-  sim <- seq_len(nchains) ## track chains that are still being simulated
+  stat_track <- rep(1, ntrees) ## track length or size (depending on `stat`)
+  n_offspring <- rep(1, ntrees) ## current number of offspring
+  sim <- seq_len(ntrees) ## track chains that are still being simulated
 
-  ## next, simulate nchains chains
+  ## next, simulate ntrees chains
   while (length(sim) > 0) {
     ## simulate next generation
     next_gen <- do.call(
@@ -335,7 +335,7 @@ simulate_summary <- function(nchains, statistic = c("size", "length"),
     indices <- rep(sim, n_offspring[sim])
 
     ## initialise number of offspring
-    n_offspring <- rep(0, nchains)
+    n_offspring <- rep(0, ntrees)
     ## assign offspring sum to indices still being simulated
     n_offspring[sim] <- tapply(next_gen, indices, sum)
 
@@ -357,7 +357,7 @@ simulate_summary <- function(nchains, statistic = c("size", "length"),
     stat_track,
     chain_type = "chains_summary",
     statistic = statistic,
-    chains = nchains,
+    chains = ntrees,
     class = c("epichains", class(stat_track))
   )
 }
diff --git a/R/stat_likelihoods.R b/R/stat_likelihoods.R
index 176494e1..af5c18b8 100644
--- a/R/stat_likelihoods.R
+++ b/R/stat_likelihoods.R
@@ -181,7 +181,7 @@ offspring_ll <- function(x, offspring_dist, statistic,
 
   # Simulate the chains
   dist <- simulate_summary(
-    nchains = nsim_offspring,
+    ntrees = nsim_offspring,
     offspring_dist = offspring_dist,
     statistic = statistic,
     ...
diff --git a/man/aggregate.epichains.Rd b/man/aggregate.epichains.Rd
index b4797d85..1582c810 100644
--- a/man/aggregate.epichains.Rd
+++ b/man/aggregate.epichains.Rd
@@ -25,7 +25,7 @@ Aggregate cases in \verb{<epichains>} objects by "time" or "generation"
 \examples{
 set.seed(123)
 chains <- simulate_tree(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
diff --git a/man/check_nchains_valid.Rd b/man/check_nchains_valid.Rd
deleted file mode 100644
index 1a20e8b5..00000000
--- a/man/check_nchains_valid.Rd
+++ /dev/null
@@ -1,15 +0,0 @@
-% Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/checks.R
-\name{check_nchains_valid}
-\alias{check_nchains_valid}
-\title{Check that nchains is greater than 0 and not infinity}
-\usage{
-check_nchains_valid(nchains)
-}
-\arguments{
-\item{nchains}{Number of chains to simulate.}
-}
-\description{
-Check that nchains is greater than 0 and not infinity
-}
-\keyword{internal}
diff --git a/man/check_ntrees_valid.Rd b/man/check_ntrees_valid.Rd
new file mode 100644
index 00000000..67b8dac6
--- /dev/null
+++ b/man/check_ntrees_valid.Rd
@@ -0,0 +1,15 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/checks.R
+\name{check_ntrees_valid}
+\alias{check_ntrees_valid}
+\title{Check that \code{ntrees} is greater than 0 and not infinity}
+\usage{
+check_ntrees_valid(ntrees)
+}
+\arguments{
+\item{ntrees}{Number of trees to simulate.}
+}
+\description{
+Check that \code{ntrees} is greater than 0 and not infinity
+}
+\keyword{internal}
diff --git a/man/simulate_summary.Rd b/man/simulate_summary.Rd
index a453d680..71c0af9f 100644
--- a/man/simulate_summary.Rd
+++ b/man/simulate_summary.Rd
@@ -5,7 +5,7 @@
 \title{Simulate transmission chains sizes/lengths}
 \usage{
 simulate_summary(
-  nchains,
+  ntrees,
   statistic = c("size", "length"),
   offspring_dist,
   stat_max = Inf,
@@ -13,7 +13,7 @@ simulate_summary(
 )
 }
 \arguments{
-\item{nchains}{Number of chains to simulate.}
+\item{ntrees}{Number of trees to simulate.}
 
 \item{statistic}{String; Statistic (size/length) to calculate. Used to
 determine stopping criteria for simulations when \code{stat_max} is finite.
@@ -92,7 +92,7 @@ where \code{...} are the other arguments to \verb{simulate_*()}.
 
 \examples{
 simulate_summary(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
diff --git a/man/simulate_tree.Rd b/man/simulate_tree.Rd
index 568d86e3..79954c2a 100644
--- a/man/simulate_tree.Rd
+++ b/man/simulate_tree.Rd
@@ -5,7 +5,7 @@
 \title{Simulate transmission trees from an initial number of infections}
 \usage{
 simulate_tree(
-  nchains,
+  ntrees,
   statistic = c("size", "length"),
   offspring_dist,
   stat_max = Inf,
@@ -16,7 +16,7 @@ simulate_tree(
 )
 }
 \arguments{
-\item{nchains}{Number of chains to simulate.}
+\item{ntrees}{Number of trees to simulate.}
 
 \item{statistic}{String; Statistic (size/length) to calculate. Used to
 determine stopping criteria for simulations when \code{stat_max} is finite.
@@ -41,7 +41,7 @@ called \code{n}, that returns a numeric vector of \code{n} randomly sampled seri
 intervals. See details.}
 
 \item{t0}{Start time (if serial interval is given); either a single value
-or a vector of same length as \code{nchains} (number of simulations) with
+or a vector of same length as \code{ntrees} (number of simulations) with
 initial times. Defaults to 0.}
 
 \item{tf}{End time (if serial interval is given).}
@@ -115,7 +115,7 @@ where \code{...} are the other arguments to \verb{simulate_*()}.
 \examples{
 set.seed(123)
 chains <- simulate_tree(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
diff --git a/tests/testthat/test-checks.R b/tests/testthat/test-checks.R
index d0b619f0..a9d4313b 100644
--- a/tests/testthat/test-checks.R
+++ b/tests/testthat/test-checks.R
@@ -12,15 +12,7 @@ test_that("Checks work", {
     "must be a function"
   )
   expect_error(
-    check_serial_valid(function(x) rep("a", 10)),
-    "numeric"
-  )
-  expect_error(
-    check_serial_valid(function(x) 3),
-    "vector of length"
-  )
-  expect_error(
-    check_nchains_valid(1.1),
+    check_ntrees_valid(1.1),
     "less than"
   )
 })
diff --git a/tests/testthat/test-epichains.R b/tests/testthat/test-epichains.R
index 58daf454..1232fcb9 100644
--- a/tests/testthat/test-epichains.R
+++ b/tests/testthat/test-epichains.R
@@ -22,14 +22,14 @@ test_that("Simulators return epichains objects", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -38,7 +38,7 @@ test_that("Simulators return epichains objects", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -85,14 +85,14 @@ test_that("print.epichains works for simulation functions", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -101,7 +101,7 @@ test_that("print.epichains works for simulation functions", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -133,14 +133,14 @@ test_that("summary.epichains works as expected", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -149,7 +149,7 @@ test_that("summary.epichains works as expected", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -157,7 +157,7 @@ test_that("summary.epichains works as expected", {
   #' Simulate case where all the chain statistics are Inf
   set.seed(11223)
   epichains_summary_all_infs <- simulate_summary(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -239,14 +239,14 @@ test_that("validate_epichains works", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -255,7 +255,7 @@ test_that("validate_epichains works", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -301,14 +301,14 @@ test_that("is_chains_tree works", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -317,7 +317,7 @@ test_that("is_chains_tree works", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -359,14 +359,14 @@ test_that("is_chains_summary works", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -375,7 +375,7 @@ test_that("is_chains_summary works", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -402,7 +402,7 @@ test_that("aggregate.epichains method returns correct objects", {
   set.seed(12)
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -439,7 +439,7 @@ test_that("aggregate.epichains method throws errors", {
   expect_error(
     aggregate(
       simulate_tree(
-        nchains = 10,
+        ntrees = 10,
         statistic = "size",
         offspring_dist = "pois",
         stat_max = 10,
@@ -455,7 +455,7 @@ test_that("aggregate.epichains method is numerically correct", {
   set.seed(12)
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -463,7 +463,7 @@ test_that("aggregate.epichains method is numerically correct", {
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -508,14 +508,14 @@ test_that("head and tail print output as expected", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -551,14 +551,14 @@ test_that("head and tail return data.frames", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
diff --git a/tests/testthat/test-simulate.R b/tests/testthat/test-simulate.R
index 29354fda..8cc039ab 100644
--- a/tests/testthat/test-simulate.R
+++ b/tests/testthat/test-simulate.R
@@ -22,14 +22,14 @@ test_that("Simulators work", {
   )
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
   )
   #' Simulate a tree of infections with serials
   tree_sim_raw2 <- simulate_tree(
-    nchains = 10,
+    ntrees = 10,
     statistic = "size",
     offspring_dist = "pois",
     stat_max = 10,
@@ -38,7 +38,7 @@ test_that("Simulators work", {
   )
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -67,7 +67,7 @@ test_that("Simulators work", {
   expect_true(
     all(
       simulate_tree(
-        nchains = 10,
+        ntrees = 10,
         statistic = "size",
         offspring_dist = "pois",
         stat_max = 10,
@@ -82,7 +82,7 @@ test_that("Simulators work", {
 test_that("simulate_tree throws errors", {
   expect_error(
     simulate_tree(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = "s",
       statistic = "length",
       lambda = 0.9
@@ -91,7 +91,7 @@ test_that("simulate_tree throws errors", {
   )
   expect_error(
     simulate_tree(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = "lnorm",
       statistic = "length",
       meanlog = 0.9,
@@ -101,7 +101,7 @@ test_that("simulate_tree throws errors", {
   )
   expect_error(
     simulate_tree(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = s,
       statistic = "length",
       meanlog = 0.9,
@@ -111,7 +111,7 @@ test_that("simulate_tree throws errors", {
   )
   expect_error(
     simulate_tree(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = "pois",
       statistic = "size",
       lambda = 0.9,
@@ -121,7 +121,7 @@ test_that("simulate_tree throws errors", {
   )
   expect_error(
     simulate_tree(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = c(1, 2),
       statistic = "length",
       lambda = 0.9
@@ -130,7 +130,7 @@ test_that("simulate_tree throws errors", {
   )
   expect_error(
     simulate_tree(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = "pois",
       statistic = "size",
       lambda = 0.9,
@@ -143,7 +143,7 @@ test_that("simulate_tree throws errors", {
 test_that("simulate_summary throws errors", {
   expect_error(
     simulate_summary(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = "s",
       statistic = "length",
       lambda = 0.9
@@ -152,7 +152,7 @@ test_that("simulate_summary throws errors", {
   )
   expect_error(
     simulate_summary(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = "lnorm",
       statistic = "length",
       meanlog = 0.9,
@@ -162,7 +162,7 @@ test_that("simulate_summary throws errors", {
   )
   expect_error(
     simulate_summary(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = s,
       statistic = "length",
       meanlog = 0.9,
@@ -172,7 +172,7 @@ test_that("simulate_summary throws errors", {
   )
   expect_error(
     simulate_summary(
-      nchains = 2,
+      ntrees = 2,
       offspring_dist = c(1, 2),
       statistic = "length",
       lambda = 0.9
@@ -226,7 +226,7 @@ test_that("simulate_tree is numerically correct", {
   set.seed(12)
   #' Simulate a tree of infections without serials
   tree_sim_raw <- simulate_tree(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
@@ -297,7 +297,7 @@ test_that("simulate_summary is numerically correct", {
   set.seed(12)
   #' Simulate chain statistics
   chain_summary_raw <- simulate_summary(
-    nchains = 2,
+    ntrees = 2,
     offspring_dist = "pois",
     statistic = "length",
     lambda = 0.9
diff --git a/vignettes/epichains.Rmd b/vignettes/epichains.Rmd
index 1c6fbf90..6d6c979f 100644
--- a/vignettes/epichains.Rmd
+++ b/vignettes/epichains.Rmd
@@ -199,7 +199,7 @@ serial_func <- function(x) {
 }
 
 sim_tree_eg <- simulate_tree(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
@@ -222,7 +222,7 @@ mean of $0.9$.
 set.seed(123)
 
 simulate_summary_eg <- simulate_summary(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
@@ -269,7 +269,7 @@ serial_func <- function(n) {
 }
 
 sim_tree_eg <- simulate_tree(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
@@ -283,7 +283,7 @@ summary(sim_tree_eg)
 set.seed(123)
 
 simulate_summary_eg <- simulate_summary(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
@@ -309,7 +309,7 @@ serial_func <- function(n) {
 }
 
 sim_tree_eg <- simulate_tree(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
@@ -334,7 +334,7 @@ serial_func <- function(n) {
 }
 
 sim_tree_eg <- simulate_tree(
-  nchains = 10,
+  ntrees = 10,
   statistic = "size",
   offspring_dist = "pois",
   stat_max = 10,
diff --git a/vignettes/interventions.Rmd b/vignettes/interventions.Rmd
index 2176283f..4b445c31 100644
--- a/vignettes/interventions.Rmd
+++ b/vignettes/interventions.Rmd
@@ -45,7 +45,7 @@ We simulate 200 chains tracking up to 99 infections:
 
 ```{r simulate_chains}
 sims <- simulate_summary(
-  nchains = 200, offspring_dist = "nbinom", stat_max = 99, mu = 1.2, size = 0.5
+  ntrees = 200, offspring_dist = "nbinom", stat_max = 99, mu = 1.2, size = 0.5
 )
 ```
 
@@ -70,7 +70,7 @@ For example, to reduce R by 25% at the population level we scale the `mu` parame
 
 ```{r simulate_chains_pop_control}
 sims <- simulate_summary(
-  nchains = 200, offspring_dist = "nbinom", stat_max = 99, mu = 0.9, size = 0.5
+  ntrees = 200, offspring_dist = "nbinom", stat_max = 99, mu = 0.9, size = 0.5
 )
 sims[is.infinite(sims)] <- 100 # Replace infections > 99 with 100 for plotting.
 ggplot(data.frame(x = sims), aes(x = x)) +
@@ -107,7 +107,7 @@ Having defined this, we can generate simulations as before:
 
 ```{r simulate_chains_ind_control}
 sims <- simulate_summary(
-  nchains = 200, offspring_dist = "nbinom_ind", stat_max = 99, mu = 1.2,
+  ntrees = 200, offspring_dist = "nbinom_ind", stat_max = 99, mu = 1.2,
   size = 0.5, control = 0.25
 )
 sims[is.infinite(sims)] <- 100 # Replace infections > 99 with 100 for plotting.
@@ -137,7 +137,7 @@ This can be likened to a disease control strategy where gatherings are limited t
 
 ```{r simulate_chains_truncated}
 sims <- simulate_summary(
-  nchains = 200, offspring_dist = "nbinom_truncated", stat_max = 99, mu = 1.2,
+  ntrees = 200, offspring_dist = "nbinom_truncated", stat_max = 99, mu = 1.2,
   size = 0.5, max =  10
 )
 sims[is.infinite(sims)] <- 100 # Replace infections > 99 with 100 for plotting.
diff --git a/vignettes/projecting_incidence.Rmd b/vignettes/projecting_incidence.Rmd
index 63f9eb53..b147ff72 100644
--- a/vignettes/projecting_incidence.Rmd
+++ b/vignettes/projecting_incidence.Rmd
@@ -227,7 +227,7 @@ sim_chain_sizes <- lapply(
   seq_len(sim_rep),
   function(sim) {
     simulate_tree(
-      nchains = length(t0),
+      ntrees = length(t0),
       offspring_dist = "nbinom",
       mu = mu,
       size = size,