say i want to change the charactars appearence throughout the game. e.g. add armour or swithc weapons ect. how do i do it. also, how do i add combat into a game. turnbased that is
I'm not sure about the combat, but to change appearence; you could use the change view code on the interations menu.
Let me tell you something. A battle engine isn't easy to make, but there are a lot of topics on it, so search it up and you'll find it out. If your prepared to make your own engine, then by all means do so.
I can't think of a solution for the characters. The only thing I can think of would take along time. Maybe you could use overlays?
Since you'll need to script the turn-based stuff anyways, here's the script command to permanently change a character's appearance:
http://www.adventuregamestudio.co.uk/manual/Character.ChangeView.htm
About the engine, what R4L said, basically. This is a complex task, and there are numerous ways to approach it, so don't expect a ten sentences long step-by-step guide.
Learn the scripting language, browse the technical forums, Beginner's FAQ and manual, start with a simple game.
When you are ready to ask specific questions about how a certain issue can be resolved, come back here, and we'll gladly help you.