How do you determine your attack?

Question

For instance: a spell says "Int vs AC" Do you roll raw int + d20 vs AC?

Do you roll Int bonus + d20 vs AC?

Do you roll int bonus+weapon accuracy +d20 vs AC? (This is a question about swordmage, so I have a melee weapon AND cast spells)

Please help. We've been confused on this and it seems like it'd be pretty crazy to just take int bonus +d20

Answer 1

How to make attack rolls is described on pages 215-7 of the Rules Compendium in pretty good detail. To sum it up. The Player's Handbook has a smaller version on page 274.

When making an attack roll add the following to 1d20:

1. The modifier for the attack power the character is using. This will be a stat bonus + 1/2 of the character's level.
2. The permanent modifiers to the attack.
   • Magic weapon bonus
   • Proficiency bonus
   • Feat bonuses
3. The temporary modifiers to the attack.
   • Combat Advantage
   • Cover
   • Concealment

Ideally a player should know the sum of #1-2 for each power they possess. Then they'd only need to handle the temporary modifiers.