include challenges, competitive or co-operative gameplay, win-loss conditions and states, feedback loops, and how they relate to one another. Like game balance itself, the terminology behind game mechanics can vary in game studies depending on the game designer or the resource's author. Buffs and nerfs In simple terms, buffs improve game elements (and sometimes game mechanics), while nerfs worsen them. These are methods in which the game adjusts the challenge for the player. Both can be achieved indirectly by changing other elements and mechanics, or introducing new ones. Both terms can also be used as verbs for the act of making such a change. The first established use of the term "nerf" was in Ultima Online, as a reference to the Nerf brand of toys due to their soft toy bullets. However, there is no concrete evidence to show where the term "buff" came from. It has been perceived that the term came from bodybuilding culture, where it is a slang term which refers to an individual's large musculature as a result of strength-based exercises. The most popular use of these terms is found in most MMORPGs, where game designers use buffs and nerfs to maintain game balance shortly after introducing a new feature that may cause significant changes to the game's mechanics. This is sometimes due to a method of using or acquiring the object that was not considered by the developers. The frequency and scale of nerfing vary widely from game to game, but almost all MMOs have engaged in nerfing at some point. Nerfs in various online games, such as Anarchy Online, have spurred in-world protests. Since many items in virtual worlds are sold or traded among players, a nerf may have an outsized impact on the virtual economy. As players respond, the nerf may cause prices to fluctuate before settling down in a different equilibrium. This impact on the economy, along with the original impact of the nerf, can cause large player resentment for even a small change. In particular, in the case of items or abilities which have been nerfed, players can become upset over the perceived wasted efforts in obtaining the now nerfed features. For games where avatars and items represent significant economic value, this may bring up legal issues over the lost value. Skill Skill is generally divided into the ability to make decisions and the dexterity to execute them via an input