DDO is based on the 3.5 Edition rule set, NWO on the 4th Edition rule set, and AoW on...well, I have no idea. Being a phone app they took D&D to a completely different style of play. Basically, you selected one of several pre-made characters, tweaked the looks (albeit on a very limited basis), and then jump right in to fighting classic D&D monsters in, well, as you might have guessed, an "arena".
DDO has been around for over 8 years, NWO just recently finished it's 1-year anniversary event, and AoW was released in October of last year. It has evolved somewhat over the last 9 months, adding 'companions', and the ability to "power-up" your companions, to name a couple. They also added new "events" that, while they have the same basic play style, have an "adversary" that has special attack abilities. But if you haven't downloaded AoW, I wouldn't bother at this point.
Why? Because a notice was sent through the app yesterday that on August 31, AoW will be "retired and the servers will be turned off". It won't even make 1-year.
Kind of makes me wonder just how bad someone had to screw up to not even last one year....
