To make testing even easier, I found this technique will work well (thanks @Dragofer for the suggestion): Just place the pk4 in any FM you're actively playing, then in-game open the console with the ~ key and use the following cheat code: spawn atdm:ammo_flasharrow inv_ammo_amount 50 This spawns an arrow in front of the player which gives you 50 flash arrows when picked up. No need to modify any map and add ammo items to test it.