diff --git a/R/fabricate.R b/R/fabricate.R
index 54ed2c3..335dfc0 100644
--- a/R/fabricate.R
+++ b/R/fabricate.R
@@ -51,43 +51,20 @@
 #'
 #' @export
 fabricate <-
-  function(data = NULL,
-           N = NULL,
-           ID_label = NULL,
+  function(data,
+           N,
+           ID_label,
            ...) {
     options <- quos(...)
 
-    functions_or_not <-
-      sapply(options, function(i) {
-        is_lang(get_expr(i))
-      })
-
-    if (length(functions_or_not) > 0) {
-      options_fn <-
-        sapply(options[functions_or_not], lang_name) ## function names
-      if (any(options_fn == "level") &
-          !all(options_fn == "level")) {
-        stop(
-          "Arguments passed to ... must either all be calls to level() or have no calls to level()."
-        )
-      }
-      all_levels <-
-        all(options_fn == "level") &
-        length(options_fn) > 0 & all(functions_or_not)
-    } else{
-      all_levels <- FALSE
-    }
+    all_levels <- check_all_levels(options)
 
-    if (!is.null(data) & !any(class(data) == "data.frame")) {
+    if (!missing(data) && !"data.frame"  %in% class(data)) {
       stop(
         "Please provide a data object to the data argument, e.g. a data.frame, tibble, or sf object."
       )
     }
 
-    ID_label <- substitute(ID_label)
-    if (!is.null(ID_label)) {
-      ID_label <- as.character(ID_label)
-    }
 
     # check if all the options are level calls
     if (all_levels) {
@@ -95,7 +72,7 @@ fabricate <-
         # Pop the data from the previous level in the current call
         # Do this if there existing data to start with or
         #   and beginning with the second level
-        if (i > 1 | !is.null(data)) {
+        if (i > 1 | !missing(data)) {
           options[[i]] <- lang_modify(options[[i]], data_internal_ = data)
         }
 
@@ -111,12 +88,21 @@ fabricate <-
       return(data)
 
     } else {
+      if(missing(data)) data <- NULL
+      if(missing(N)) N <- NULL
+      if(missing(ID_label)) ID_label <- NULL
+
+      ID_label <- substitute(ID_label)
+      if (!is.null(ID_label)) {
+        ID_label <- as.character(ID_label)
+      }
+
       fabricate_data_single_level(
         data = data,
         N = N,
         ID_label = ID_label,
         existing_ID = !is.null(data) & is.null(ID_label),
-        ... = ...
+        options = options
       )
     }
   }
@@ -127,60 +113,89 @@ fabricate_data_single_level <- function(data = NULL,
                                         N = NULL,
                                         ID_label = NULL,
                                         ...,
-                                        existing_ID = FALSE) {
-  if (sum(!is.null(data),!is.null(N)) != 1) {
+                                        existing_ID = FALSE,
+                                        options=quos(...)) {
+  if (is.null(data) == is.null(N)) {
     stop("Please supply either a data.frame or N and not both.")
   }
 
-  if (is.null(data)) {
-    if (length(N) > 1) {
-      stop(paste0(
+  if (!is.null(N)) {
+    if (length(N) != 1) {
+      stop(
         "At the top level, ",
         ID_label,
         ", you must provide a single number to N."
-      ))
+      )
     }
-    # make IDs that are nicely padded
-    data <-
-      data.frame(sprintf(paste0("%0", nchar(N), "d"), 1:N), stringsAsFactors = FALSE)
-
-    # this creates column names from ID_label
-    # note if ID_label is NULL that the ID column name is just "ID" -- so safe
-    colnames(data) <- ifelse(is.null(ID_label), "ID", ID_label)
-  } else {
+    data <- data.frame()
+    existing_ID <- FALSE
+  } else if(!is.null(data)){
     N <- nrow(data)
-    if (existing_ID == FALSE) {
-      data[, ifelse(is.null(ID_label), "ID", ID_label)] <-
-        sprintf(paste0("%0", nchar(nrow(data)), "d"), 1:nrow(data))
-    }
   }
 
-  args <- quos(...)
-
-  args_names <- names(args)
-
-  if (length(args) > 0) {
-    for (i in 1:length(args)) {
-      # this was changed to move costly data.frame operations inside the loop
-      #   because previously, if you did rnorm(N) in a level
-      #   it literally did a vector of length N, rather than doing
-      #   it for all of the values of the level above it, i.e. if this
-      #   this is the second level and N = 2, it made a vector of length 2
-      #   even though there were 5 units in the higher level so there should
-      #   have been a vector of 5*2 = 10
-      # NB: this is still not super safe; if the expression returns a thing
-      # of length not exactly to N it's just going to repeat it as it does
-      # data.frame(data_list). Usually this shouldn't be a problem but we may
-      # want a warning or error
-      data_list <- as.list(data)
-      data_list$N <- N
-      data_list[[args_names[i]]] <-
-        eval_tidy(args[[i]], data_list)
-      data_list$N <- NULL
-      data <- data.frame(data_list, stringsAsFactors = FALSE)
-    }
+  if (!existing_ID) {
+    if(is.null(ID_label)) ID_label <- "ID"
+    data <- genID(data, ID_label, N)
+  }
+
+
+  fab(data, options)
+}
+
+# make IDs that are nicely padded
+genID <- function(data, ID, N=nrow(data)){
+  fmt <- paste0("%0", nchar(N), "d")
+  data[1:N, ID] <- sprintf(fmt, 1:N)
+  data
+}
+
+fab <- function(data, args) {
+  N <- nrow(data)
+  for (i in names(args)) {
+    if(i == "") next #Unnamed args are meaningless?
+
+    # this was changed to move costly data.frame operations inside the loop
+    #   because previously, if you did rnorm(N) in a level
+    #   it literally did a vector of length N, rather than doing
+    #   it for all of the values of the level above it, i.e. if this
+    #   this is the second level and N = 2, it made a vector of length 2
+    #   even though there were 5 units in the higher level so there should
+    #   have been a vector of 5*2 = 10
+    # NB: this is still not super safe; if the expression returns a thing
+    # of length not exactly to N it's just going to repeat it as it does
+    # data.frame(data_list). Usually this shouldn't be a problem but we may
+    # want a warning or error
+    data_list <- as.list(data)
+    data_list[[i]] <-
+      eval_tidy(args[[i]], append(data_list, list(N=N)))
+
+    #TODO Factor this out of loop? It's expensive
+    data <- data.frame(data_list, stringsAsFactors = FALSE, row.names=NULL)
+    args[[i]] <- NULL
   }
 
-  rownames(data) <- NULL
   return(data)
 }
+
+check_all_levels <- function(options){
+
+  if (length(options) == 0)  return(FALSE)
+
+
+  is_function <- sapply(options, function(i) {
+      is_lang(get_expr(i))
+  })
+
+  is_level <- "level" == sapply(options[is_function], lang_name) ## function names
+
+  if(length(is_level) == 0) return(FALSE)
+
+  if (any(is_level) != all(is_level)) {
+    stop(
+      "Arguments passed to ... must either all be calls to level() or have no calls to level()."
+    )
+  }
+
+  is_level[1] && length(is_level) == length(options)
+}
+
diff --git a/R/level.R b/R/level.R
index 88050c6..0153ed1 100644
--- a/R/level.R
+++ b/R/level.R
@@ -32,37 +32,7 @@ level <-
 
       ## if data is not provided to fabricate, this part handles the case
       ##   of the top level, where data must be created for the first time
-      if (is.null(N)) {
-        stop(
-          paste0(
-            "At the top level, ",
-            ID_label,
-            ", you must provide N if you did not provide data to fabricate."
-          )
-        )
-      }
-      if (length(N) > 1) {
-        stop(paste0(
-          "At the top level, ",
-          ID_label,
-          ", you must provide a single number to N."
-        ))
-      }
-
-      # make IDs that are nicely padded
-      data_internal_ <-
-        data.frame(sprintf(paste0("%0", nchar(N), "d"), 1:N), stringsAsFactors = FALSE)
-      colnames(data_internal_) <- ID_label
-
-      # now that data_internal_ is the right size, pass to "mutate", i.e., simulate data
-
-      options <- lang_modify(dots,
-                             data = data_internal_,
-                             N = NULL,
-                             ID_label = ID_label)
-      level_call <- quo(fabricate_data_single_level(!!!options))
-
-      return(eval_tidy(level_call))
+      return(fabricate_data_single_level(N=N, ID_label=ID_label, options=dots))
 
     } else {
       # at the second level, after data is created, or at the top level if data is provided
@@ -80,14 +50,7 @@ level <-
                             N = N)
 
         # now that data_internal_ is the right size, pass to "mutate", i.e., simulate data
-
-        options <- lang_modify(dots,
-                               data = data_internal_,
-                               N = NULL,
-                               ID_label = ID_label)
-        level_call <- quo(fabricate_data_single_level(!!!options))
-
-        return(eval_tidy(level_call))
+        return(fabricate_data_single_level(data_internal_, NULL, ID_label, options=dots))
 
       } else {
         # otherwise assume you are adding variables to an existing level
@@ -103,18 +66,7 @@ level <-
           unique(data_internal_[, unique(c(ID_label, level_variables)),
                                 drop = FALSE])
 
-        # set up
-        options <- lang_modify(
-          dots,
-          data = data,
-          N = NULL,
-          ID_label = ID_label,
-          existing_ID = TRUE
-        )
-
-        level_call <- quo(fabricate_data_single_level(!!!options))
-
-        data <- eval_tidy(level_call)
+        data <- fabricate_data_single_level(data, NULL, ID_label, existing_ID = TRUE, options=dots)
 
         return(merge(
           data_internal_[, colnames(data_internal_)[!(colnames(data_internal_) %in%
diff --git a/man/fabricate.Rd b/man/fabricate.Rd
index d854cf0..756b5b8 100644
--- a/man/fabricate.Rd
+++ b/man/fabricate.Rd
@@ -5,7 +5,7 @@
 \alias{level}
 \title{Fabricate data}
 \usage{
-fabricate(data = NULL, N = NULL, ID_label = NULL, ...)
+fabricate(data, N, ID_label, ...)
 
 level(N = NULL, ...)
 }