Grinding is the act of doing something repetitively, such as killing monsters or working up a trade skill. If one is grinding their levels, it usually refers to killing massive amounts of creeps. If one is grinding for reputation, they may be collecting items for repeatable quests for a particular faction.
In older MMORPGs, such as EverQuest, grinding was the primary way to advance your character's level. The quest system was very underdeveloped, as opposed to the quest system in World of Warcraft. This is one of the reasons that World of Warcraft has received much praise, as the game has less of a treadmill feeling than its predecessors.
Grinding does have some advantages over questing. If one chooses to ignore quests for the most part, or even entirely, they have an enhanced chance of finding world drops, which they may either use or sell for large amounts of gold. Also, if one grinds their professions, they can easily surpass the average skill level of their peers and be able to craft much more powerful items. Grinding reputation with some factions yields substantial rewards (especially with the advent of World of Warcraft: The Burning Crusade) such as Timbermaw Hold or the Scryers.
- Before going out to grind levels, make sure that you know what you are going to kill. For example, dense crowds of low-level mobs may actually give more experience per time than a powerful single mob, especially for classes with strong AoE abilities.
- Grinding in a party may lower the amount of progress or loot any one player makes per fight, but also makes those fights much quicker.
- Two grinders need not have conflicting interests. For example, players often allow skinners to tailgate them because they take 'loot' the player cannot use, while the skinner reciprocates by helping in fights (once the original player tags a mob) while not reducing the amount of xp the original player gets. This is especially useful with large level disparities which would severely reduce the amount of experience a character may get if partied.
- Make sure you stock up on restorative items to reduce backtracking and overall downtime.
- Keep in mind that being rested doubles the experience for killing a monster.
- When grinding reputation from kills (as opposed to from drops), you get the same amount of reputation per kill regardless of how many players are in your party. Because of this, it is faster to grind kill reputation in groups.