In some Doom versions having a backpack also doubles the amount gained from picking up ammo.

The above sentence needs to be justified or expanded. It's necessary to point out on what version or variant this occurs. It may also be irrelevant or not applicable in the article or at the top of the article if it refers to an adaptation that changes the game a lot (which is likely the case). Who is like God? 09:42, 25 April 2008 (UTC)