“DDO combat has elements of twitch in it. The short course is this: WASD movement, right mouse button swings your weapon. Two right clicks in short succession perform a swing and then a backhand swing. Holding down the shift button raises your shield to block (or allows you to tumble using the WASD keys if you have the skill). By watching monster combat animations you can see when they are going to attack, or use a special attack, and time it so you can block it/tumble out of the way.”
However, later things get ugly:
“There is no player economy to speak of (and no easy mechanism for one), no housing, no exploration beyond exploring the quest instances themselves, no pvp, no crafting, no elder game, and no wookie table dancing.”
f13.net - Impressions of Dungeons and Dragons Online