Pro-Pain! is a video game from the King of the Hill episode, "Grand Theft Arlen". The game is an obvious parody video game (based on gameplay) on the Rockstar game series, "Grand Theft Auto" video game series. It is created by several college students which are providing an "Active Electronic Lifestyles" course at Tom Landry Middle School. The students become enamoured with Hank Hill's life as a propane salesman and create a game to emulate his life, and him, in Arlen, Texas.
Initially, when it is released, Hank is tasked by Buck Strickland to investigate the potential impact it may have upon Strickland Propane and other trademarks or terms which Buck has, or has intended to own, as it references his company and Hank directly.
Hank, after discovering that the main character, himself, can be promoted, becomes addicted to the game on the "single player" option before finally discovering the online multiplayer via Bill Dauterive. Bill himself uses the game as a form of escapism insofar as it emulates Hank's life, which makes him a natural target for the more aggressive players on the game, which include Bobby's classmate, Dooley.
Buck discovers that the game is released in the Public Domain, and as such, does not constitute any legal infringement on his copyrights, but Hank continues to play the game at work and at home.
The game as shown in the series has a progression through the ranks of the propane industry as shown in the show, with the highest being an exclusive "Commissioner" mode. Hank raises his rank and experience, but is eventually defeated by Peggy, who is made "Comissioner" by the gamecreators. Peggy's character was designed to close the whole gaming network upon the character's death, which was caused by Peggy herself. Once Peggy's character "PQSmoove" explodes, the entire game ends and Hank is freed from his "addiction".
References are made which poke fun at the "Grand Theft Auto" franchise, with a specific weapon being a "Pimp Cup", which Hank uses to slap Peggy's character when his various other weapons cause damage. Players on the game also throw propane tanks at each other, causing explosions, which Hank rightly says does not happen.