The home system of the designer of 4th Edition D&D (Rob Heinsoo) and the designer of D&D v3.0 (Johnathan Tweet) published as 13th Age. Heavily story-driven, the game combines many of the variable class powers from 4th Edition D&D with the d20 system of D&D 3.5, while disposing of the miniature combat focus shared by those games.
Ranked in these QuestionsQuestion Ranking
Pros
Pro The game is built for people who've done it before
The world is half built, letting you get in and leave your mark. Each class plays mechanically different than other d20 versions. Skills are placed by backgrounds. It's a short hand and interesting way of playing DnD.
Pro Long lists of skills are gone completely
And covered by backgrounds (much like FATE or Cortex+) so that players aren't searching through lists of skills and what they can do constantly.
Pro Gonzo without the grid
13th Age has some very gonzo fights with party combos, lots of variable powers for monsters and PC's but as a simple set of rules for combat that speed it up without losing a lot of options.
Cons
Con Too similar to 4th
Con The Icons and the PC relationships to them can confuse
Can be confusing, especially for new players.