Can someone please explain action-based combat.

I've played many MMOs and I guess I never really gave a **** as to what the name of the combat was in each game I played. DAOC, WoW WHammer, EVE, Aion, Rift ect.. all seemed to all have the same type of combat. Someone please explain....

Play Tera (currently FTP) and you'll have a pretty good idea of action combat. In short you don't need to target something to hit it. Your shots and swings don't magically home in on your target. If you miss you miss, if you hit you hit. No random dice roll to determine if you hit or missed. It is typically a higher learning curve and skill cap for personal performance.

Yes, play TERA. It has similar combat + it's amazing

Or alternatively Skyrim