I played a tad bit of LoL, and can't say I was WoWed (lulz pun). League of Legends is not an RTS game by any means.
Which means that comparing it to Starcraft II, Civilization, or any other RTS game won't do it the proper justice.
I would venture that it's more like Gauntlet Legends or Smash TV in the style of gameplay, only with other players as the enemy rather than hordes of easily killed monsters followed by boss fights. So if you've played Gauntlet Legends and thought to yourself, "Hey, this game would be so much better if there were four other people on the opposing side fighting me and my friends tactically" then I would recommend League of Legends.