diff --git a/.scripts/TobyCustom/.dependencies b/.scripts/TobyCustom/.dependencies
new file mode 100644
index 0000000..f6f7564
--- /dev/null
+++ b/.scripts/TobyCustom/.dependencies
@@ -0,0 +1,23 @@
+check_dependencies() {
+    if [[ $# -lt 2 ]]; then
+         dialog --backtitle "Linux Game Manager" \
+                --msgbox "Invalid call to check_dependencies(). Please check your code." -1 -1 --stdout
+        exit 1
+    fi
+    local packagePath="$1" # Path where the launcher will attempt the package, e.g. ${gamePath/Addons/PACKAGENAME/something.pk3
+    local packageURL="$2" # URL where the package can be downloaded.
+    shift 2
+    if [[ -e "${packagePath}" ]]; then
+        return
+    fi
+    local message=(
+        "You are missing the \"${packagePath##/*}\" Package." $'\n'
+        "You can get it from \"${packageURL}\"" $'\n')
+    echo "${packageURL}" | DISPLAY="${DISPLAY:-:0}" xclip -selection clipboard && message+=("The URL has been copied to the clipboard." $'\n')
+    for i in "${@}" ; do
+        message+=("$i" $'\n')
+    done
+    dialog --backtitle "Linux Game Manager" \
+        --msgbox "${message[*]}" -1 -1 --stdout
+    exit 1
+}
diff --git a/.scripts/TobyCustom/ArmyOfDarknessDoom.sh b/.scripts/TobyCustom/ArmyOfDarknessDoom.sh
index 4a4123d..ab35d6a 100755
--- a/.scripts/TobyCustom/ArmyOfDarknessDoom.sh
+++ b/.scripts/TobyCustom/ArmyOfDarknessDoom.sh
@@ -1,7 +1,8 @@
 #!/usr/bin/env bash
 
-# requires aoddoom1.wad
-# https://www.moddb.com/mods/army-of-darkness-total-conversion/addons/army-of-darkness-doom-wad
+# check for required wad.
+source ${0%/*}/TobyCustom/.dependencies
+check_dependencies "aoddoom1.wad" "https://www.moddb.com/mods/army-of-darkness-total-conversion/addons/army-of-darkness-doom-wad" "Place \"aoddoom1.wad\" in \"${gamePath}\"."
 
 
 gamePath=~/.local/games/doom