Well, in your example I would be sure to let the players make pretty easy Int/knowledge rolls to know that:

  1. The Wizard is much higher level than the players
  2. Wizards never leave their towers unguarded
  3. The amount of time and resources they are going to have to expend trying to rob the Wizard will be dungeon crawl level difficulty at least.
  4. They can't rescue the Priest if they are dead or in jail themselves.


And that's just the beginning. What alignment are the characters? Unless they are a lot lower on the morals scale than Neutral Good, they probably won't have the moral infortitude to rob an innocent bystander.

Or you could just let the rogue case the place and find out it's going to be too tough of a nut to crack at their level.

Or you could let them break in and find out that the Wizard doesn't just leave his valuables laying around for would-be thieves and has an account at the local bank.

Or you could let them break in and found out that the Wizard is actually dead broke and isn't on vacation, he's been evicted, and that the place is completely empty.

Basically, you will eventually develop the creative muscle to be able to come up with stuff on the fly. That kind of skill comes with experience. The more experience you get, the better your off-the-cuff responses to player Machiavellianism will get.