Oozy Goodness Part II: Gelatinous Cube

Ah the gelatinous cube. A slime-based entity that apparently evolved to accommodate graph paper. It's probably fair to say that the cube is an iconic D&D monster. Even if a player hasn't had to deal with one himself, chances are he knows the basic idea of the thing: It slides along corridors slurping up organic debris. They are quiet, hard to see, and dissolve people.

Gelatinous Cube (from Moldvay)

AC: 8
HD: 4*
Move: 60' (20')
Att: 1
Damage: 2d4 + special
No. App: 1 (0)
Save: F2
Morale: 12
Treasure: V
AL: N

As we can see, old blocky here shares certain traits with other slimers: It's none to fast, it's got a high morale (mindless), and isn't too hard to hit. Their strength as a foe comes largely from the fact that the are "nearly transparent" and surprise quite often (1-4).

The other big deal about the GC is of course its paralyzing attack. Similar to a Ghoul's, the effect only lasts 2d4 turns and can be removed with Cure Light Wounds. Of course, if a character fails their save and is paralyzed while the cube is busily trying to devour him, a few turns is plenty of time to finish off a victim.

Gelatinous cubes aren't horrifically tough, mind you. As long as a party member or two stays clear, they can likely finish one off in a few rounds. Interestingly, the cube is immune to electrical and cold attacks, but fire does the trick nicely. Lobbing flask of burning oil from a distance is a favorite tactic of many adventurers.

A cube has no lair, and its meager treasure type (V) reflects this somewhat. There's always a chance of some coins or gems stuck undissolved in the goo, but probably not much. Far more interesting is for a DM to deliberately place something the PCs want or need within the cube to make dealing with the creature more necessary.

DMs should play up how hard it is to spot a cube in a dark dungeon corridor as well as its chance at surprise. Once the PCs know its there, chances are the bulk of the danger is gone. Conversely, players should rely on ranged attacks (often after some poor soul has gotten paralyzed to reveal the threat) as well as flaming oil or similar.

Cubes can also be incorporated into traps and ambushes. If there is some evil lich or some such "Dungeon Boss" that has stocked his lair with creatures to keep out interlopers, cubes can be used to up the ante. Spiked pit? Yawn. Pit with a cube in the bottom? Now yer talkin'! Or perhaps the cube does the falling. Trap the PCs in a 10 x 10' stretch of hallway with portcullis traps and have the cube fall out of a ceiling panel onto them.