[hcobb]

Peter LaNore has pointed out that Analyze Magic at ITL 23 gives false results if the spell fails, but that a wizard can tell if the spell failed unless she rolls exactly 17 because of this logic:

Success costs her 4 fatigue.
Most failures cost her only 1 fatigue.
A roll of 18 knocks her over.
Only a roll of 17 fails silently and costs her 4 fatigue.

The same problem applies to Detect Life, Duplicate Writing, and Trance, but Pathfinder and Spellsniffer have their own failure rules.

A similar issue applies to Long-Distance Teleport.