Tarrasque killing challenge!

[Douglas]

Assume a single level 1 human sorcerer has 16 Cha, and has taken the feats 'Skill focus: UMD' and 'Magical Aptitude'. This sorcerer has full ranks (4) in UMD, giving him a total of +12 to his UMD. (+5 from feats, +4 from skills, +3 from stats)

This sorcerer is then given a wand of Acid Arrow with only 1 charge in it. Such a wand would cost:

4500/50 = 90 gp

60% of the time the sorcerer will succeed in his UMD attempt, doing 2d4 damage for 2 rounds. This averages to 5 damage per round for 2 rounds. This damage bypasses SR and DR.

First, UMD is a cross-class skill for Sorcerers so the max ranks is 2, not 4. Second, Acid Arrow is on their class list so they don't need UMD to use the wands anyway. They do, however, have to succeed on the ranged touch attack. This amounts to not rolling a 1 vs the Tarrasque's touch AC of 5, but it still needs to be accounted for.