I made a small competitive map (between the size of Asylum and Zealot) that supports CTF, Assault, KOTH, HH, and Oddball. I was thinking about just making one respawn zone for each team that gives each team one half of the map to respawn in to act as a universal respawn zone for all gametypes. Would that cause any problems you can think of? I'm just trying to cut down on the number of objects on the map. Correct me if I'm wrong, but I'm aware that universal respawn zones can assist in spawn killing for slayer and mess some other things up too. I think my map is small enough and has enough cover to where that won't be a problem. What do you think?
What you're proposing to do is called static spawning and is fine for certain maps. Asylum and Countdown have static spawning for all gametypes, and basically all maps have it for objective games. I'd have to see the map to make an informed recommendation. Basically though I think static spawning is appropriate for most maps except arena-style, very small maps (where it's better to give every team the ability to spawn anywhere, just so it's harder to get spawn-killed), or maps where there's no way to split it in half without giving one team a huge advantage (this is probably why High Ground in Halo 3 had static spawns for objective games, but dynamic spawns for team slayer). The important part of doing all static spawning is that it shouldn't give one team too much of an inherent advantage, and both sides need enough protected, separate areas to spawn in that spawn-trapping isn't too easy to accomplish. For what you're trying to do, just create one respawn zone for each team. In slayer mode there's an object label TEAM ONLY - use that and set the respawn zones to game specific = true. That should cause them to be active in all team games but inactive in FFA.
TEAM_ONLY also is NOT recognized by Infection, meaning that if you use this label, you will have betrayed humans and zombies spawning anywhere on the map. If you want zombies to spawn on one half of the map and betrayed humans to spawn on the other side, assign nothing to the GAME TYPE LABEL and just assign teams to the Respawn Zones. Team assigned Respawn Zones are never used in FFA...
That's true Green, however often times you'll want the spawn areas for infection to be different than the ones for team games. Using TEAM_ONLY works well in this case because it lets you set up infection-specific red and blue spawn zones without any conflicts.