Probably one of the best all around explanations of the EQ melee combat system, including many effects and stats. Briefly, there are two types of attack in the attack stat, similar but in opposition to the AC stat. One portion has to do with actually hitting an opponent (let's call it the accuracy component) and one part with damage dealt. Offense and Weapon skills apply attack soley to the accuracy component, while item attack stats and strength apply to the damage portion. The link explains it better and in more detail.
Just to clarify what I already said, and what CandaraFR said, Attack score based on Offense and Weapon Skill will increase you're successful to unsuccessful hit ratio, however, Attack boosts from equipment's Attack stat will not (EDIT for clarity: but will slide the average hit damage up). Dmg is based on a minumum (Dmg Bonus) plus a variable amount. Attack that deals with damage increases the probability of higher amounts of the variable part, so you hit closer to the maximum more often.
Yther Ore. Edited, Feb 1st 2012 3:06am by Yther Edited, Feb 1st 2012 4:53pm by Yther