Warriors are often powerful melee fighters capable of dealing heavy damage and wearing the strongest of armors. Due to their exceptional melee skills, they often have little to no magic capabilities. While they are proficient in the use of many types of weaponry, they are not often the one dealing out the most damage. Their role often entails maintaining the attention of the enemy and using their defenses to mitigate the damage.
In EverQuest, warriors are the tanks of Norrath. They don't deal the most damage, but they are second to none in mitigating damage. Warriors come equipped with various melee skills including bash, dual wield, double attack, parry, riposte, dodge, taunt, and disarm. Although they wield all of these abilities, they have absolutely no magic ability, which means they cannot solo very well. Even a great warrior is dependent upon a great partner or team to keep him/her standing toe-to-toe with th enemy. Their main task is keeping th enemy at hand focused on him/her so that the rest of his/her team can do what they do best uninterrupted. So, while warriors need others to excel, everyone needs a good warrior. They can wear any of the four types of armor, but would be unwise not to wear plate as soon as it becomes available to them.