Attack Rating is displayed on the Character Screen. It shows the percentage chance that you will hit the target, as well as the chance of the targeted monster hitting you. If your Attack Rating is too low, you will notice that your attacks often miss. The chance to hit increases if you are at a higher character level than the monster you're attacking. Your Attack Rating can be improved by increasing your Dexterity, and by equipping magic items that specifically increase your Attack Rating.

In multiplayer, it should be noted that the actual chances to hit a monster may appear to be much lower than what is displayed on the character sheet. This may be due to multiple reasons including server lag which results in your character being too far away from the monster (in the case of melee attacks) to properly connect with his attacks. Confirmation of this effect can be seen in crowded environments (Arcane Sanctuary and Maggot Lair notably) where on one player's screen compared to another, characters occupy different locations. Using a melee attack like smite (which always hit) and still missing also indicate that the target is out of range. Moving away then re-engaging the target usually re-evaluates the character's position and may fix the issue.