[Kromm]

Originally Posted by martinl

Crit fails probably result in the user folding out an aggressive tentacle instead of the tool they wanted, wight?

Too predictable!

On any critical failure on a task (e.g., Armory, Forced Entry, Lockpicking, or Surgery roll) using the Universal Multitool™, assess the usual critical-failure result and roll 3d:

3 – Universal Multitool™ accidentally cuts a hole in reality. An Elder Thing of the GM's choosing steps through and attacks.
4, 5 – Universal Multitool™ extrudes an Eldritch Tentacle (see Against the Rat-Men, p. 19). Tool cannot be recovered until this is defeated, though it can be left there, if the owner doesn't mind parting with a $51,000 item. Tentacle's first attack on the wielder is always a surprise attack.
6, 7 – Universal Multitool™ warps reality subtly. Person carrying it suffers from Weirdness Magnet for 1d days. If not carried by anyone, the timer doesn't advance – 1d days of weirdness must afflict someone.
8 – Universal Multitool™ does something unspeakable. User must roll a Fright Check.
9, 10, 11 – Normal critical-failure result only.
12, 13 – Universal Multitool™ emits an otherworldly squeal. Roll at once for wandering monsters, at +3 if there's any chance of Elder Things appearing.
14 – Universal Multitool™ folds in upon itself and won't work for 1d days.
15 – Universal Multitool™ extrudes the wrong tool. Object being repaired, person being repaired if using Surgery, or the user's hand in other cases suffers 2d HP of injury or the usual damage from a critical failure, whichever is worse.
16 – As 15, but injury is 3d HP.
17 – Universal Multitool™ accidentally cuts a hole in reality, falls through, and is lost forever. (If the owner has Signature Gear, they may opt to jump through after it. Alone. Outside Time and Space, where the Elder Things are.)
18 – As 17, except the owner is dragged along with the tool. Roll vs. DX to let go in time. Failure means ending up Outside Time and Space.