Action - video game genre that emphasizes physical challenges, including hand–eye coordination and reaction-time
AFK - AFK is "Away From Keyboard"
Aggro - AGRO is "Hostile, angry" or "Aggravation, trouble"
AI - (artificial intelligence) is the simulation of human intelligence processes by machines, especially computer systems.
Boss - boss is a significant computer-controlled enemy
Buff - (video gaming), a change to a weapon or ability that deems it more viable for game balance
CRPG - Computer Role Playing Game
DLC - Downloadable Content. Most commonly used when referring to DLC for PC games or current gen consoles
FPS - Frames per second (FPS) is a unit that measures display device performance
GG - Good Game
Hitbox - A hitbox is an invisible shape commonly used in video games for real-time collision detection
Hotfix - single, cumulative package that includes information that is used to address a problem in a software product
Lag - noticeable delay between the action of players and the reaction of the server in a video game