The gravislayer is a creature from the Spelljammer campaign setting.

2nd Edition StatsEdit

Climate/Terrain: Wildspace, asteroid fields

Frequency: Very rare

Organization: Solitary

Activity Cycle: Constant

Diet: Nil

Intelligence: Semi- (2-4)

Treasure: Nil

Alignment: Neutral evil

No. Appearing: 1

Armor Class: 0

Movement: 24

Hit Dice: 8+1

THAC0: 13

No. of Attacks: 0

Damage/Attack: Nil

Special Attacks: Gravity slam

Special Defenses: Nil

Magic Resistance: Nil

Size: M (6' diameter)

Morale: Steady (11-12)

XP Value: 3,000


The gravislayer is a navigational hazard hated by spelljammers throughout the Known Sphere. Its unremarkable body hides one of the most destructive forces known.

The gravislayer's body is a sphere of flesh roughly six feet in diameter, scarred and pitted from the rigors of deep space patrolling. There are no eyes, ears, or other features readily visible on its grayish surface; there is a large mouth that opens up only during feeding. A gravislayer feeds on the crushed flesh and bone of unsuspecting spacefarers that are smashed to bits by the creature's deadly command of gravity.


The gravislayer's weapon is its ability to change gravity. It can turn any single object within 150 yards into a powerful gravity source. That object may be a living being, an asteroid, or even a character. The object remains a gravity source for as long as the gravislayer concentrates.

The gravislayer's weapon relies on two things: the availability of objects to fall onto new gravity sources and how far those objects fall before impact.

Availability of Objects: Anything that falls for a period of time picks up great momentum and causes vast damage upon impact. A gravislayer usually turns its victims into gravity sources, hoping that asteroids will fall upon them to destroy them.

For purposes of gravislayer combat, asteroids are divided into three categories. Pebbles are stones weighing less than one pound. Boulders weigh in the neighborhood of 100-1,000 pounds. Finally, planetoids weigh more than 10,000 pounds. Note: Every object, be it an asteroid, piece of a spaceship, or a chest of gold, should be placed into one of these categories.

The numbers and sizes of asteroids available to a gravislayer depend upon its immediate surroundings.

Asteroid Availabllity – Numbers and Sizes
Deep Space Orbit Rings Asteroid Field
Pebble 1d4-2 1d4-1 2d6 2d6
Boulder 1d4-3 0 1d6 2d6
Planetoid 0 0 0 1d4-2

Falling Time: Each asteroid, regardless of size, takes 1d6 rounds to fall onto the target (roll for each asteroid). The damage caused depends on the asteroid size and on the number of rounds it fell. A successful saving throw vs. breath weapon negates all damage inflicted by pebbles and boulders and half damage from planetoids.

Hit Points of Damage, By Rounds Fallen
1 2 3 4 5 6
Pellet 1d4 3d4 6d4 10d4 15d4 21d4
Boulder 1d6 3d6 6d6 10d6 15d6 21d6
Planetoid 1d12 3d12 6d12 10d12 15d12 21d12
Hull Damage, By Rounds Fallen
1 2 3 4 5 6
Pellet 1d4 2d4 3d4 4d4 5d4 6d4
Boulder 1d6 2d6 3d6 4d6 5d6 6d6
Planetoid 1d12 2d12 3d12 4d12 5d12 6d12

If the gravislayer is destroyed before the asteroids strike the target, those asteroids are then much easier to avoid (roll a saving throw vs. breath weapon against each, with a bonus of 5, plus 2 for every round until impact). Common tactics for ship crews is to immediately locate gravislayers and destroy them as quickly as possible, then deal with the falling asteroids.


Gravislayers have no known planet of origin or societal inclinations. Shipboard tales speak of a cult of nebulords, wizards of tremendous power, who were enemies of the reigar. The nebulords created gravislayers for their own purposes, turning them loose throughout space.


No gravislayers have ever been captured for examination, so their means of reproduction is uncertain. They may have none. A gravislayer is immune to the gravity that it creates. It is not, however, immune to naturally occurring gravity.


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