Requires GZDoom 4.4.0 or higher!
Description
Corruption Cards is a gameplay mod for Doom (and others) which presents the player with three random cards each level. These cards effect the gameplay in different ways, some more subtle than others. The effects range from changing monster behavior, adding new mechanics, adding extra hazards and much more! In the standard mode, you will be offered a permanent card every 3 levels. This card will be locked in for the rest of the game, meaning you will have to live with your choice until the game is over! There are now over 50 unique cards, and more are generated as the game is played. Every run you will be offered different cards, which leads to an ever changing gameplay experience... dictated by your card choices!
Corruption Cards works with all sorts of mods, and will even generate custom cards for any new monsters it detects! Give it a try with your favorites to spice up the gameplay and add a little extra challenge

Screenshots
Spoiler:
Downloads
< Corruption Cards Version 1.0 >
Corruption Cards Version 3a (outdated, for use with Zandronum)
Compatibility Patch Files
These are files for mods I could not fix without altering the code myself, and have to rely on patch wads:
Brutal Doom v21 - Removes Imp and ZombieMan from card generation so these monsters don't die on map start.
What's next?
I will be working on a couple of projects throughout the year, but I plan to do periodic updates to this to add new cards and features. I will be rolling out cards in batches at a time so you don't have to keep downloading the mod to get new content. I put quite a lot of thought into what cards I make for this mod, as I want it to be a fair and fun experience. Having said that though, I already have some fun ideas lined up, so stay tuned

If you've enjoyed what you've played, consider supporting me on my ko-fi page. Thanks

Changelog
Spoiler:
V4B
- Added 2 new cards I forgot to push onto the cards list!
- Added a glowing effect to the permanent card choice.
- Cards will no longer be generated for actors inherited by monsters (such as Zombieman corpses) and monsters flagged as FRIENDLY.
- Reduced the damage of toxic corpses (1-4 instead of 4-8).
- Adjusted X Monster Respawns card tier (+2).
- Improved spawning for Monster Gangs, Random Cyberdemon etc.
- God Monsters can no longer be targeted by other monsters.
- Fixed a reflective monsters crash.
- Fixed a 16th kill card crash and improved the monster spawning.
- Made barrel spawning staggered to improve the framerate on map start. Also reduced the max barrel count (ignores stacking).
- Dodging monsters now ignore damage and afterimages copy any colours (translations) they had.
- Improved Inventory Reset card. It now takes away any weapons, invbar items, armor and backpacks and gives you your class base items.
- DEHACKED monsters are no longer replaced, and should function properly. However, extreme DEHACKED modifications will still have issues elsewhere (i.e D4V has a lot of problems).
- The game now laughs at you if you pick a high tier mystery card.
V5A
- Fixed another crash with the 16th kills card.
- Fixed a crash with the Monster Disguise card.
- Fixed monster gang permenant cards not working after the first map they were chosen.
- Fixed "remove half the items" not actually removing half the items.
- Fixed "remove half the items" removing custom Key replacements.
- Fixed the earthquake permenant card only triggering once.
- Fixed vanilla monsters having the incorrect wing colour.
- Commander Keen no longer gets cards.
- Adjusted hud ids to avoid conflicts with other mods calling hudmessage at the start of the game.
- Added new Demon and Spectre attack cards (vanilla only).
- Generated monster cards now effect all monsters of that species (custom monsters only).
V6A
- Fixed a eventhandler crash on startup wtih certain mods (i.e embers of armageddon).
- Fixed yet another crash with 16th kills card (check your null pointers, kids!).
- Fixed 16th kills card occasionally spawning more than one monster at once.
- Added new effects for the 16th kills card.
- Fixed monsters buffs losing their effect when resurrected.
- Improved Boss/Gang spawns a bit more.
- Changed freezing the players at the start of game to be more reliable.
- Changed card generation changed to not offer card types already chosen with the same monster species.
- Permanent Partial Invisibility effects monsters aim but doesn't make you or your hud translucent.
- Repsawning monsters no longer effect all its species.
- Respawning monsters card is now always tier 5.
- Respawning monsters time to respawn now scales with monster health.
- Respawned monsters no longer count towards the kill count.
- Slighly reduced the base damage of Corpse Explosions.
- Wounded monsters damage buff changed: Damage now scales the more damaged the monster is, up to 200% damage.
- Added new effect to the wounded monster damage buff.
- Earthquakes no longer effect Keys.
- Spawned barrels now disappear when telefragged (You still also get protection from these barrels after teleporting).
- Added 6 new cards, and 7 new vanilla monster altering cards!
V7B
- Removed Mystery cards from normal play modes. After looking at feedback and my own personal experience, most players just loaded a save if they picked a terrible card effect. Though I love the sadistic nature of getting screwed by RNG, it's not everyone's cup of tea and not something you always want in your runs. Custom rules can still enable Mystery Cards if desired.
- Improved DEHACKED compatability with mods that have minor monster changes.
- Improved hand generation to never show multiple of the same monster altering card for different monsters.
- Fixed Monsters hunting players at the start of the map not waking up.
- Fixed a crash with Monster Disguise.
- Fixed a bug where disguised monsters + monsters hunt players cards would create invisible ghost monsters.
- Fixed a crash with Heal Effects.
- Fixed Archvile Keyguards card showing up in Doom 1.
- Fixed wounded buff sounds and monster colour not showing correctly.
- Fixed earthquakes moving voodoo dolls, which broke some maps.
- Fixed Dodge effect to copy the monster's scale factor and renderstyle.
- Fixed no monster infight card being flagged as stackable.
- Fixed reflective monsters adding monsters to the projectile modifier pool (i.e if a reflective Demon was shot with a plasma ball, a "demons fire triple projectiles" card could be generated).
- Removed Unknown Cards card as it was a bit too mean to get in a hardcore run. Might be back in some form later.
- Removed Broken Armor from pool, as a card exists to give each monster armor breaking properties.
- Removed "Monsters hunt the player in silence" and replaced with individual monster silence cards.
- Player movement improved a little during an earthquake.
- Improved monsters getting suck with additional monster + gang cards.
- Changed how poison corpses work. Now monsters will immediately start spewing poison clouds, but for a short duration instead of forever.
- Improved "Monster starting positions are shuffled".
- Nerfed fast missiles to 1.5 speed instead of 2.0 speed (they can still stack!)
- Added a sort of hacky way to stop Additional Monsters getting stuck and clogging up monster closets.
- Added some new cards.
V8A
- Altered card generation to trim the deck if there too many generic type monster cards (i.e Imps can fly) over regular cards (i.e Earthquake). Generic cards are still favoured if there's a lot of them though.
- Fixed SwitchableDecoration monsters vanishing on map start.
- Fixed a crash with the Paranoia card.
- Fixed some crashes regarding jetpack effects (project brutality crash).
- Made newly spawned monsters from cards attempt to move after being spawned if stuck in another actor.
- Remade how reflective works. The monster will fire a new projectile back at you at full speed!
- Thanks to the above, fixed reflective monsters generating projectile cards even if they don't actually fire projectiles.
- Barrels of Fun card now spawns whatever the Explosive Barrel class is, even if it gets replaced by another mod. The barrel will fail to spawn if it is within 250 units of a teleport destination.
- Flying monsters now get a generic flying effect instead of goofy jetpacks (Jetpacks and Wings still appear on vanilla monsters).
- Added a new card. Try not to get assassinated!
V10A
- Card selection now displays all 3 card effect descriptions on the same screen, so you can see them all without having to scroll though them manually.
- Fixed game selector text spilling over into the card selector in multiplayer.
- Added the optional countdown timer to the options.
- Added a new debugging feature. "ccards_debugselection" will allow you to manually select a card from the entire card pool on the card select screen. Careful, this allows to you choose cards with non-legal conditions!
- Added optional keybinds for selecting card 1, 2 or 3. This is for people who want to program outside forces into picking your cards, such as your twitch.tv viewers
- Barrel spawning no longer attempts to spawn the barrel near monsters, as they were blocking outside monster outside the map.
- Fixed a bug where additional/child monsters were getting stuck inside their parents.
- Fixed a bug that allowed dodging monsters to able to dodge attacks every tic instead of every few seconds.
- Removed "Remove half the maps items" card, as it binary and uninteresting. Also very cruel on more resource light mods. A fun new item related card has been added to replace it.
- Added a few new cards!
V20A
- Added a new type of Generic card that replaces monster projectile attacks with another. Works with custom monsters! (EXPERIMENTAL)
- Removed vanilla monster replacements and vanilla specific cards. The only exception is the Surprise Cyberdemon card, which will check if the Cyberdemon has not been replaced before offering it.
- Fixed a crash with reflective monsters.
- Fixed a crash with cards that healed nearby monsters.
- Fixed a crash with triple projectiles causing an infinite loop when projectiles were being duplicated some other way (like with Champions triple projectile effect)
- CCARDS lump now requires the "addcard" word to add a new card class to the game.
- CCARDS lump supports the "removecard" word for card classes. This removes a card that has already been added in a previous CCARDS lump. "Clearcards" removes all of them.
- CCARDS lump supports the "excludemap" word for map codes i.e MAP01. This allows you to add a map code to tell the game to not offer you a card on this map. Useful for hub maps etc.
- CCARDS lump supports the "dontfreeze" word for actors. This allows you to tell the game to not freeze/unfreeze an actor at the start of the game.
- CCARDS lump supports the "excludeactor" word for actors. This allows you to tell the game to not attempt to generate cards for a specific actor. Useful for when modders like to flag props as ISMONSTER for some reason.
- Acid Rain is no longer stackable (it didn't do anything).
- Assassin monsters are now Fast monsters.
- Anti-grav is no longer listed as a buff card.
- 16th spawner card now only spawns monsters found in the map, and also tries to avoid spawning them in walls.
- God Monster card recoded to fix some bugs. Also now only requires 90% of the maps monsters to be killed in order to revert back to normal.
- More cards!
V20B
- Fixed replacement projectiles getting stuck in midair if the projectile was blocked upon spawning.
- Added a different SwitchableDecoration fix. These actors will no longer get caught by the Thinkers trying to unfreeze them on spawn (triggering their Active/Deactive states), and are now ignored.
- (Multiplayer) Key binds for selecting a card now check for the correct player.
- You can now use the Use key for Card/Game selection instead. You can toggle which key (or both) in the options.
V21A
- Fixed lots of missing sprites and sounds. Doh!
- Attempted to fix monsters that rescaled themselves after being shrunk by a card effect.
- Improved compatibility (now works with QCDE monsters).
- Fixed a bug with CCARDS unfreezing any actor defined in it.
- Added 3 new cards!
V22A
- Implemented long term difficulty scaling.
- Possibly fixed a crash with the Earthquake card.
- Fixed a multiplayer crash with Rain effects.
- Fixed a crash with the Acid Blood buff.
- Inverted Gravity card now reads "(monster) can invert its gravity". Monsters with this buff can now toggle their inverted gravity on and off as they see fit.
- Inverted Gravity card re-added to the Buff pool.
- Small monsters now have higher pitched sounds.
- If a card is picked for you (i.e chaos mode), you will now get a preview of the card on screen.
- Fixed some sounds not playing.
V22B
- Lowered the duration of the card preview in Chaos Mode.
- Fixed a crash with fast projectiles.
- Fixed another crash with Acid Blood. Acid Blood is no longer created by Acid Blood!
- Fixed curse cards and God monster card effecting only one level when chosen as a permanent card.
- Fixed the minature army clones immediately taking damage upon spawning.
V23B
- Fixed a crash with (custom) small card pools.
- Added 'noprojectilereplacement' option to CCARDS. This disables all projectile replacement card generation.
- Seed will now be shown on the console at the start of each map.
- Nerfed acid blood damage.
- Monster Gang sizes are reduced for monsters with lots of health.
- God monster damage nullification sounds are no longer global. Also added sparkles.
- God monster translation is reset if it is manually changed by a mod.
- Earthquakes no longer cause monsters to instantly attack upon seeing the player.
- Optimization for monsters picking up items. Items carried by monsters can no longer be picked up.
- Added one new card.
V23C
- Added extra protection for projectile replacers to prevent infinite loops with projectiles that spawn projectiles.
- Tripled and Replaced projectiles now copy any inventory tokens over from the old projectile. This is to try to fix crashes with mods like champions.
- Fixed monster healing cards not respecting monsters that have had their SpawnHealth changed via scripts etc.
- Fixed a very mod specific crash with earthquakes.
- Bullet attack replacement no longer effects species.
- Removed the Inventory Reset card as it is often an unwanted pick, plus it breaks a lot of mods.
V24B
- Fixed vanilla monsters not using custom wing graphics.
- Fixed flight effects remaining on corpses.
- Fixed a lock up with Acid Blood and Heal Effect actors. Effects are capped so prevent ludicrous amounts of actors spawning.
- Fixed a bug with the special card.
- Sludge Rain now slows down the player more.
- Keys of Power now announce what buff monsters receive.
- Keys of Power can no longer give duplicate buffs.
- Random buffs no longer include the base buff class, which gave them no buff (whoops).
- Lowered volume of god monster sound when damaged.
- Card images are now compiled images, which makes them still appear correctly if mods change the Doom graphics.
- Changed a couple of card images.
- Fixed a bug which cause certain cards to not function upon loading a save game (curse cards).
- Fixed a rare crash with the 16th kill card.
V25A
- Added support for Heretic.
- Fixed barrel/misc spawning at the start of levels causing massive fps drops. These actors will spawn in the map at a slightly slower rate.
- Changed projectile detection so Heretic monsters can generate projectile related cards.
- Changed projectile replacing slightly. New projectiles spawned from a monster will now try to use the projectile's original defined speed, if it exists.
- Fixed Ninja Dodging effects.
- Fixed a bug where certain replaced projectiles would not seek targets (i.e Revenant Missiles).
- Fixed wings not showing for the vanilla Demon. Also some other wing offset fixes.
- Added an effect for Acid Blood infused monsters.
- Monster effect particles are no longer spawned if no players can see the monster.
- Nerfed Acid Blood damage slightly when triggered by bullet weapons.
- Reduced the duration of Blood Rain.
- Effects that used vanilla Doom sprites have been imported for consistency with mods.
- Added three new cards.
V1.0
- Added joystick support for card/selection. Enabling the joystick will also allow you to select using the mouse (sort of).
- "Projectile are now seekers" card now greatly improves seeker targeting if the projectile is already a seeker.
- Duplication Curse now has a limit to how many monsters can be duplicated.
- Cleaned up options menu a bit.
- Fixed shield sounds not working.