That’s a common refrain. I hear ya. I’ve had players go ballistic, shouting that the ooze “breaks the rules.”
But I’d say the Ooze is one of the most quintessentially Torchbearer monsters because it is only deadly at the end of a series of failures. As you know, it’s not like every time you go to find water an ooze pops out. The ooze twist makes sense because the GM decided to place it there, and the GM can sell it through foreshadowing and details in the room description so that it doesn’t seem like a gotcha’.
In additional to the failed test, the players must also have ignored clues leading up to it that something would be amiss:
- The crypt is cursed
- The environment is blighted
- There is nothing else in the room
- There is water dripping from the faucet
- They spent time hanging around it
As with any adventure though, GMs will edit to the tastes of the table. I’ve run Skogenby without ever pulling the ooze out. It’s plenty deadly without it.