RyanMcRae asked about this in another thread: "In the first adventure, I'm super unclear how the goblins are supposed to defeat the ooze. "
Me too! I wouldn't say the goblins are "supposed to" defeat the ooze. In fact, I haven't seen it happen yet. That said, it could be possible.
- It is clearly weakened by light and the site is full of mirrors and the bright coruscate orb. If the ooze was drenched in enough light, the goblins could attack from a 'good position' and do pretty well.
- The runed axe that Blance the warrior is carrying does say: "Does one additional harm to magic creatures (such as the Tenebrous Ooze) and cannot be conven- tionally destroyed." It could be very useful if the Goblins get hold of it.
- Parts of the ooze were stored in runed jars in a cold safe. The ooze's cell walls are coated in runes. If the goblins copied the runes, they might be able to re-imprison it.
There are opportunities for clever approaches, and several groups have used them to flee with minimal losses. None so far have 'won'. This tone is carried through other adventures as well. Goblins are small and scrappy and won't always solve huge, inscrutable problems like the ooze. So far groups who have run through the Pit of Mirrors have enjoyed what victories they've earned.