From Chainmail to D&D Next
I added this because it new, and It think it directly competes with d&D 5th edition. It is a sci-fi exploration game, but it’s a discovery and exploration game like early D&D. The system has some neat parts, nothing revolutionary, put likely the first time they have been brought to the main stream. The best being how to define a character with a simple sentence: "I am an adjective noun who verbs.” Cypher one time use magic items are good idea, and keeps players seeking them.
This is a Monte Cook game as he thinks of a narrative game. But I do not find it to be a true narrative game. It has some neat ideas and a beautiful setting. One of which being how difficulties are determined and character stats reduce that difficulty or that GM does not roll dice, but is given the ability to cause intrusions. Numenera really feels like D20 done almost right. He borrowed a lot of ideas for Indie game and made them traditional. He did a lot of things that other games have failed at like experience is both how you advance your character and a currency to improve a roll.
Play this game when you want to play a Sci-FI exploration game, and you like Monte Cook. He done amazing job of putting a lot of ideas together into a playable game.