The Gelatinous Cube is a classicDungeons & Dragonsmonster, known for its eerie transparency and its ability to dissolve nearly anything in its path. It lurks in dungeons, waiting for unsuspecting adventurers to stumble into its jelly-like body, or to drop on them from above.
Running a Gelatinous Cube encounter can be a fun challenge for Dungeon Masters, as it’s not just about brute strength—this creature requires strategic thinking and clever tactics from the party. Whether planning a one-shot or a full campaign, here are ten tips to make your next Gelatinous Cube encounter both thrilling and memorable.
8Use Tight Spaces
Limit Mobility For Added Tension
Gelatinous Cubes are most dangerous in narrow, enclosed areas where the party has limited room to maneuver. Place them in tight hallways or small rooms to restrict the players’ movement, so they must interact with it even if they see it beforehand.
The cube’s large size and slow speed can easily trap adventurers, making it harder for them to escape. By using confined spaces, you increase the tension, forcing players to think strategically about their positioning, since the environment is often the cube’s ally.
7Emphasize Its Transparency
Surprise Players With Its Invisibility
One of the Gelatinous Cube’s most iconic traits is its near-invisibility, so you can use this to your advantage by having the players walk without realizing they’re heading straight into the cube. Describe the dungeon as suspiciously clean or littered with dissolved equipment—small hints that something is off.
If your players aren’t careful, they could end up trapped inside the cube before they know what’s happening. This surprise factor makes for a memorable moment and sets the tone for a tense, dangerous encounter right from the start.
6Exploit Its Engulf Ability
Trap Players Inside the Cube
The Gelatinous Cube’s most fearsome ability is its Engulf, which allows it to trap creatures inside its body, slowly dissolving them. Once a character is trapped, they take acid damage each round and have to fight their way out.
Use this ability to create a sense of urgency—once a character is engulfed, the party will scramble to free them before it’s too late. The cube’s engulf ability makes it a mix betweena creature and an obstacle—it’s an active threat that forces the players to act quickly or face serious consequences.
5Incorporate Environmental Hazards
Pair The Cube With Dungeon Traps
A Gelatinous Cube isn’t just a monster—it’s part of the dungeon environment. Pair the cube with traps likepressure plates, spike pits, or collapsing wallsto create even more chaos during the encounter.
Players may be focused on avoiding the cube’s slow-moving body, only to trigger a trap that complicates their escape. By using traps alongside the cube, you ensure that the encounter feels like an integrated part of the dungeon, rather than a standalone monster fight.
4Have The Cube Fall From Above
Players Don’t Often Look Up
The transparency of the Gelatinous Cube makes it ideal for hiding in plain sight, but sometimes hiding out of sight is better. If the cube is sticking to the ceiling (something they can’t often do, but it is a popularhomebrewed ability), you may raise the difficulty of the check to find it.
you’re able to also place it right on top of some treasure, possibly dropped by the cube; a sword or shield held by its last meal. Then it just drops into the unsuspecting party, possibly engulfing more than one victim in a single move, an ideal trap for high-level adventurers.
3Add Loot Inside The Cube
Rewards For Risk-Takers
A fun way to add some intrigue to the encounter is by placing valuable loot inside the Gelatinous Cube. Describe the shimmering outline of a sword or treasure chest trapped within the cube’s body, possibly being corroded to add urgency to the decision-making.
Players may be tempted to dive in and retrieve the loot, knowing they’ll have to deal with the cube’s engulfing ability. This adds an element of risk versus reward, encouraging players to weigh their options and decide if the treasure is worth the danger.
2Use Its Slow Speed To Build Tension
Imminent Danger, But Slow-Approaching
Gelatinous Cubes aren’t fast, but they are relentless. Use the cube’s slow speed to build suspense, giving the players time to react but also a sense of impending danger as it slowly advances toward them, particularly in contexts where they don’t have the means to fight back.
This can lead to moments of panic as players try to escape, knowing the cube is inching closer with every turn. The cube’s slow speed makes the encounter feel more like a horror scenario, as players will be desperate to stay out of its path while managing other threats in the dungeon.
1Reward Creative Solutions
Encourage Thinking Outside The Box
While brute force can defeat a Gelatinous Cube, the best encounters are those that reward creative thinking. Encourage your players to come up with innovative solutions, like using fire to corral the cube, luring it into a trap, or using spells like Misty Step to teleport out of its reach.
The Gelatinous Cube’s simplicity as a monster allows for more inventive tactics, so give your players the space to experiment. By rewarding creativity, you make the encounter more memorable and engaging, ensuring that it stands out from a typical monster fight.
