You and AbdulAlhazred make some excellent points towards this discussion - particularly in relation to "Exploration Mode" skills. In regards to "Combat" skills however, with the 20th level Wizard, he or she is going to have a lot of hit points and so what can the 2nd level assassin achieve? Particularly with a book interpretation of what hit points represent. The 20th level wizard within 6 seconds is still going to be standing while the assassin's a puddle on the floor. Can the spot check truly be considered a "fail" or just an obscure blip on the encounter radar?
Fine. A second level Thief who picks the pocket of the 20th level Wizard, taking his epic level wand and walking out the door. The Wizard walks to the bar, orders a drink, and has no concept that he lost his best and most valuable item.
The problem is the same.
