A free app for Windows, by CutmanMike.

Corruption Cards is a gameplay mod for Doom, and other games. The gameplay is presented with three random cards each level. It is a way to add a little extra challenge and spice up the gameplay, which is why it is compatible with all sorts of mods. It will even generate custom cards for any new monsters it detects.

The effects are more subtle than others. Some of them change the way the player moves or the way the monsters attack. It is possible to see a difference in the gameplay with and without the cards. It is not a permanent change, but it is a change that is added to the game.