Is it possible to add AI biped such as marines, flood, covenant etc into a multiplayer in game? or is this only possible if you are editing maps?
like for example if I started say blood gulch on a LAN server opened up devmod and typed in something and have covenant vs flood?
If you can does anyone know the codes?

You are correct Recycle Bin. You can't add AI using devmode. You can add them in sapien. Don't ask how there are a couple good tutorials on this site.

For what you are asking, it could be possible. However, the map must be "set up" before hand. What to do:
1) Create bipeds and name them
2) Create AI (that don't spawn)
3) Set a squad with an actor varient in that encounter

Compile the map. Ingame use the ai_attach command. So if I had a biped called biped1, and an encounter named ai_1, I would type:

(ai_attach biped1 ai_1)

And the biped would come alive :)

Or....you could add AI in Sapien, tick 'not initially created'and use this command:

ai_place nameofyourencounter 

To spawn them
Edited by Polamee on Jan 31, 2009 at 12:22 AM

Could you do it and make a dead body

because I always wanted to make dead bodys all over Battle Creek

Create a biped, and check "Dead" in the Properties pane.

Take note that it will disappear after a few seconds in MultipLayer though. It will not disappear in SinglePlayer

:O..... ok it does not matter then, cause I dont have a clue what any of that means lol. I just though you could spawn them in game like you can with vehicles and weapons.

You could learn...

well I once tried making some maps..... but tool really did not like me and I eventually scraped any hopes I had of being able to make maps. :|