Probing will reveal the contents of tins it hits (and mark the tins as identified so they stay revealed).

Zapping probing at a shambling horror should tell you information about its randomized stats and attacks.

Zapping a wand of probing at a wall point-blank will inform you if there is any open space (walkable terrain, ignoring monsters/objects) between you and the edge of the screen in that direction. This can be used to find vaults and closets.

Hitting a shambling horror with a probing beam describes its stats and abilities.

You can use stethoscopes (or possibly probing) on eggs to identify them.

Merge the wand of enlightenment into the wand of probing: probing gives enlightenment when zapped at yourself.

Spell of probing, in the divination school, that probes monsters based on skill:

• Unskilled limits it to touch range and gives minimal information on the monster’s status, possibly only showing HP like a stethoscope.
• Basic is still touch range but gives the usual amount of information.
• Skilled shoots a probing beam and gives some additional information.
• Expert allows you to select any space or monster in your line of sight within a radius, and gives the same information as Skilled.

The wand of probing is raised to be on par with the Skilled effects.

When Schroedinger’s Box is probed or has a stethoscope applied to it, it either reveals the housecat corpse inside or releases the live housecat as normal. Alternatively, stethoscopes give “You hear a characteristic WOM WOM WOM sound” as a reference to Bob the Angry Flower, and probing gives you “The box contains a cat that is neither alive nor dead nor alive nor dead nor… You resolve to call the YSPCA later.”

Stethoscopes and probing on a pet shows when that pet is satiated.