Rise of Immortals is a free to play game based on the largly successful MOBA or Action RTS (Multiplayer Online Battle Arena or Action Real Time Strategy, respectively) game genre. In my opinion this is a casual gamer's casual game. They basically took elements from Dota and League of Legends and simplified them to make "Babby's first MOBA".
For example, in RoI you buy items for your immortal and upgrade them. You don't build recipes for items from lesser components as you do in LoL and DotA. However, despite this game feeling simplified and at times silly, I have to admit that good times were had playing it with my roommate over the last week. If you're new to this game genre, RoI might be the right game for you to at least start out on. If it can get more people involved in the Dota-style of video gaming I'm all for it. You can download the game for free on Steam.