Is it possible to play on nightmare without monsters respawning?

I never play on nightmare because I consider it to basically be a joke difficulty level.

However, I would actually like to try doing it if it weren't for the respawning monsters. Is there some setting in zdoom or some other source port that allows you to do this, or perhaps some mod?

Yep, fast monsters (sv_fastmonsters) with 2x damage (sv_powerful_monsters) should do the trick.

...But I'm also wrong about that as proven below :(

Theoretically, -fast is what you want, though it's not exactly the same as NM without respawn.

NM doesn't affect damage.

You can create a dehacked patch that makes none of the monsters countable for kills percentage. Then you can play on -skill 5 and the monsters won't respawn, but everything else will be the same as standard NM.

NM doesn't affect damage? Oh dear...
Sorry then.

hardcore_gamer said:

I consider it to basically be a joke difficulty level

Been a while since I dusted off my copy of Masters of Doom, but wasn't it intended to be a joke in the first place?