Imba
Imbalanced
Example
The classes in Hearthstone are so imba right now that I stopped playing

Related Slang
Broken | Overpowered |
Busted | Overpowered |
Cheese | Exploitative strategy |
Buff | Strengthen |
Nerf | Weaken |
Metagame | Outside game preparation and strategies |
combo | Combination |
Gamers use imba (imbalanced) to describe games or game elements that are not quite balanced - creating gameplay that is not fun. For example, an MTG player might say the game's current meta is imba if aggressive decks can never beat more controlling decks.
Players often use imba when discussing broken or OP strategies, which are too strong to not utilize. If most players are employing (or trying to counter) the same strategy, it's likely a game is currently imba. Hopefully, the game's developers will nerf the imba elements in the future, to make the game more fun to play.