Player Health (GZDoom)

Is there any way (in GZDoom) to prevent the player's health from ever dropping below 1? (like if you wanted to make an Arcade type map with lives, and everytime the player "dies" it would return his health back to 100 and subtract one life)

No. Doom was never designed for such a style of gameplay.

not even an ACS type of thing?

Perhaps you could achieve something like what you're looking for by forcing the player to play in single-player coop mode, and having the start/spawn spot in a place where you can only leave that area a certain number of times before it seals off permanently.

Steeveeo said:

not even an ACS type of thing?

No. All you can do is hacking around this but once the health goes below 1 the player is unconditionally dead.