I'm new to modding maps, and I just want to figure out what the different tags do. For example, what is the difference between ACTOR_VARIANT and ACTOR? And what is BIPED? I know what MODE_COLLISION_GEOMETRY is, but what is a GBXMODEL? And what is a MODEL_ANIMATION? Could someone just give me a runthrough of all the tags related to characters? Thanks :)

Hey, good to have a new guy willing to learn.

Anyway to the questions you asked, a BIPED is a essentially, a character. You can put BIPEDs in the game, or you can reference them in an ACTOR_VARIENT, to make AI, or artificial intelligence, to have badguys or goodguys.

A GBXMODEL is a model that has been run through tool, and can be put in the game. BIPEDS need a GBXMODEL to work. A model can be a model of a gun, character, environment, pretty much anything. Tool is a very handy program. You need tool to make models into GBXMODELs, regular images to BITMAPs that can be put in the game, model into MODEL_COLLISION_GEOMETRY, and a lot more.

A MODEL_ANIMATION is something a BIPED or WEAPON would use to interact and move.
Example: You would need a walking ANIMATION for a BIPED to move. You would also need a shooting ANIMATION for a gun to shoot, etc. etc.

There are heaps of tutorials that can help you with this stuff, so have fun.

BIPED tags serve to set how the character interacts with the world (pathfinding radius, speed, etc), and ACTOR tags set basic AI and behaviour to be used for all characters of that type.

ACTOR_VARIANTS allow you to have multiple instances of the same character with tweaked AI and health so you can have actors that -for instance - use many different weapons and behave differently to match that. That's how you can have Rocket Flood that like to hang back and take pot shots at you and unarmed Flood that rush at you, both using the same basic tags.

If you want to go into more detail, you can ask around for a good tutorial or search for one yourself. Halo modding can be very confusing at first, but reading the available documentation can answer a lot of your questions.

Can you have an ACTOR without an ACTOR_VARIANT or vice versa? Also, I look at one of my BIPEDs with Guerrilla and it said that my sound was invalid. What does that mean?