Nerf
With computer games, nerf is another way of saying something is intentionally weakened. For example, in an MMORPG (massively-multiplayer online role-playing game), the game's programmers may nerf a certain spell or weapon ability to help balance the damage output of specific classes.
What is the opposite of nerf in games?
If a character, class, or item is not strong enough, it's buffed. The developers continue to buff and nerf until they feel everything is balanced.
Where did the term "nerf" come from?
The terms "nerf" and "nerfing" first appeared in the 1997 game Ultima Online after discovering the sword was more powerful than any other weapon. After the developers tried balancing the game by reducing the sword's power, players complained the sword now felt like playing with a Nerf sword (brand of foam sword in the real world).