Inspired by a tabletop RPG thread on Doomworld, I've been playing around with a pen and paper version of Doom. I don't really have anyone to play with, so I made it singleplayer. All maps are 5 rooms generated by dice, with a compulsory boss level every 10 maps. I tried to keep it as simple as possible, there are no skills or saving throws, just Hit/Dodge and Damage.
It's based off the Doom PC game rules, all damages and monster hitpoints are just halved. I've playtested it a little bit, it's probably way unbalanced for the high-tier monsters and I suspect someone would have to be Invincible or very lucky to defeat a Cyberdemon or Spider Mastermind, but it's at least a potentially-complete implementation up to MAP30 and beyond.
Check it out if you like. Any questions, suggestions, criticisms and comments would be greatly appreciated.
[edit] I allowed myself attaching the file to the post -- Kornel cares