DEX for pure casters and all others who use spells. What it does in regards to casting...
1. Helps determines accuracy and spell casting capability in combat.
2. Helps calculate missile(nuke)combat skills
3. Helps determine if you're interrupted when you're hit while casting a spell.
There are a total of 8 things dex is used for the other 5 most people alrdy know so I won't list them other then it helps determine if how often your weapon proc's at full strength. This is straight out of Primas official strategy guide..So hopefully this will end some of the false info being spread about int casters not needing dex.