Should my "average" PC be able to discern the potential of encountering a gelatinous cube from subtle clues?

Question

Relatively new to DnD/TTRPGs. Playing a Barb with +0 to INT and -1 to WIS. I just realized that my party might be walking right into a gelatinous cube. What is considered "average" intelligence and wisdom? Would my character be able to reason through subtle clues that we might be wandering through a cube's lair?

The context is: Our party is visiting the same incomplete dungeon for the third time. DM has explicitly stated to us through a DMNPC of very high experience that the Kobolds in the dungeon repopulate so quickly that clearing the Kobolds on the upper floors is a common activity for practicing adventurers.

The clues are:

1. We revisited the upper floors of the dungeon multiple times without delving down (this is visit #3). Upon revisiting the dungeon within 48 hours of leaving, the many, many Kobold corpses we'd left behind were gone and there was no sign a fight ever took place.

2. In this most recent visit, we delved to the third floor. The first two floors were wide open & organic caverns, but the third floor's surfaces are obviously unnaturally smooth and angular. There are small pockets along the walls about 30ft long and 10ft wide. Perfect for cube ambushes.

To reiterate, I'm not making the case that there is definitely a cube involved. Provided that my character is aware of the existence of cubes but they don't play significantly into his history, would it be reasonable for him to connect the dots and warn his party of the potential danger in the hopes of better preparing for such an encounter? I ask specifically for the purpose of avoiding metagaming.

Question Restated

Would my character logically be aware enough of a potential Gelatinous Cube ambush to provide the rest of the party with an IC warning, despite not having concrete evidence of a specific Gelatinous Cube?

Answer 1

It depends on what you find to be fun

The Alexandrian has an interesting article on Meta-Knowledge and Meta-Skill, in the context of determining whether your fresh faced level 1 adventurer knows that trolls are vulnerable to fire. I recommend you read it in its entirely, but I will paraphrase.

Simply put, this sort of meta-knowledge is impossible to put "back in the bottle". Once you as a player know this secret, you know. We can try and pretend we don't know, but humans find it very difficult to wall off this information.

But, as the author points out, if trolls or gelatinous cubes are at least somewhat common in the world, then most people would know these facts. After all, it would be weird for people to live near a bunch of trolls or delve into dungeons inhabited by gelatinous cubes and for this critical knowledge to never get passed on.

Further, I've never been face to face with a shark, and I know they can scent minute amounts of blood in the water. Your character could have picked up this knowledge like any other piece of pop culture.

The crux of the matter is whether pretending to not know is "fun". Pretending to not know what a Hound of Tindalos is makes Call of Cthulhu fun. Knowingly using poor tactics on a troll until you've suffered enough to deserve to discover the fire vulnerability is not fun.

So you must ask yourself: Would my barbarian not knowing about Gelatinous Cubes and their tell tale signs add fun to the game, or detract from it?

I don't know you, and I don't know your table; you as a group will have to decide that for yourselves.

Answer 2

If in doubt, ask your DM to let you make a lore check for your character.

Skill checks for lore / monster knowledge are an excellent way to determine if a character knows or not a particular piece of information. It can be used both ways. To coax some information from the DM or to let the player see if Uklangor the Barbarian knows about Gelatinous cubes.

It allows the DM room to breathe as well as adding some randomness to the gameplay.

If you don't want to spoil the surprise for the rest of the table, use a written note to the DM.

There's this thread on ENworld regarding exactly this subject.

This DM in particular would also reward the player for picking up the cues by either giving advantage on the lore check or an inspiration point. Or even confirming/denying it entirely.