Apocalypse World

Apocalypse World is a post-apocalyptic roleplaying game by D. Vincent Baker and Meguey Baker, published in 2010 with only an implied setting that is fleshed out by the players in the course of character creation. It was the game for which the Powered by the Apocalypse engine was developed. On release, "Apocalypse World" won the 2010 Indie RPG Award and 2011 Golden Geek RPG of the year.
A second edition was successfully Kickstarted in 2016. This edition updated some of the mechanics (HX, battle-moves, threat map, etc.), playbooks (including replacing the Operator with Maestro-D and Quarantine), and brought Meguey Baker on board as co-designer, but retained most of the original's design.
Setting.
The game's implied post-apocalyptic setting is fleshed out during character creation. Each playbook involves and provides inspiration for certain details of the setting, such as the Hardholder, who rules the local settlement and therefore has control over its size, population, and appearance. The characters' shared history is also determined in the course of character generation. Themes of the game are survival and relationships, and they come out in the "pure lethality of the game". Notably, the Master of Ceremonies (MC) is not supposed to do any planning before sitting down to the first session, so that all players have an opportunity to shape the game world collectively.
Game play.
"Apocalypse World" is an archetype-based game.
Game mechanics.
The system uses the Powered by the Apocalypse engine. It features dice-rolling checks for challenging situations of 2d6 plus a relevant stat. Results of 10+ are successes, while 7 to 9 are partial successes or hard choices, and results of 6 or less allow the MC to make a move. A notable feature of "Apocalypse World" is the inclusion of a "special move" for each class, which triggers when a character of that class meets the appropriate triggers.
The stats are Cool, Hard (Violent, Intimidating), Hot, Sharp, and Weird (Psychic), with each PC having Hx (History) with every other PC. The default playbooks include the Hardholder, the Gunlugger, the Battlebabe, the Driver, the Chopper (Gang Leader), the Hocus (Cult Leader), the Brainer (Psychic), the Savvyhead (Mechanic/Inventor), and the Skinner (artist).
Reception.
Reception was positive, with "Apocalypse World" winning numerous awards. There was praise for the streamlined nature of the game, as well as the MC job, although the inclusion of a sex move was controversial and was explicitly called out as not for children by SFSignal.