Most beasts, plants, many monstrosities, and even some undead creatures from the Monstrous Menagerie are appropriate for use and make excellent challenges for voidrunners. The list below contains a selection of non-spellcasting creatures which can be used without any changes.

Of course, if your universe contains magical and fantasy creatures, then the whole of the Monstrous Menagerie is a vital resource, and your voidrunners can battle dragons on alien planets and wizards on ancient space stations. Alternatively, magical creatures make for excellent ‘omnipotent’ beings or aliens with exotic powers–many science fiction franchises play with the idea of mythology as unexplained science. Perhaps lycanthropy is a known medical condition, a specter is a lingering psychic imprint, or ‘magic’ comes from another dimension.

Lore. Where a monster’s entry contains Arcana as a lore skill check, use Science instead.

Appearance. You may wish to alter a creature’s name or appearance from the standard Monstrous Menagerie entry–a T-rex may be some kind of fearsome alien lizard, and a wolf may have fangs and a hairless hide.

Magic vs. psionics. Magical abilities can be re-skinned as psionics.

Monsters usually encountered in space (those with a speed listed as Spacefaring Slow, Spacefaring Average, or Spacefaring Fast) are typically more powerful than terrestrial monsters of the same challenge rating. These cosmic threats are strong enough to match a party’s ship, not merely the party itself.

Spacefaring monsters of CR 3 and below have similar statistics to standard (non-spacefaring) monsters. For a battle in which a party must face a CR 4 or higher spacefaring monster without the benefit of a starship, triple the spacefaring monster’s XP and treat it as 3 standard monsters of its Challenge Rating for purposes of encounter building. For a battle in which a starship battles a CR 4 or higher standard monster, grant ⅓ of the monster’s XP and treat it as a monster of ⅓ its CR for the purposes of encounter building.

The world can be a dangerous place and the environment might pose a deadly threat all by itself. In addition to their inherent danger, encounter elements offer ways to enhance the perils of exploration challenges or combat to make both more satisfying. A duel atop a bridge or traversing a narrow crossing is all the more exciting when deadly lava runs below rather than rushing water, and a hallway fight or dungeon trap with a plethora of green slime is a different kind of challenge altogether!

Challenge Rating Increase

The challenge rating of a combat encounter or exploration challenge can be increased when an encounter element is included so long as it poses an active threat—a cage match near a volcanic pit is more dramatic, but no more dangerous than usual.

Bombarded (+2)

An area which is under constant bombardment from artillery or starship fire can be very hazardous.

Loud Noise. Creatures within the area participants can only hear sounds within 15 feet of them (except for loud, explosive noises).

World Actions

Artillery. Each creature in the area makes a DC 10 Dexterity saving throw or they take 4d6 bludgeoning damage.

Irradiated (+2)

Deadly radiation fills the air, threatening the lives of all who brave exposure.

Every five minutes a creature spends in an irradiated area it must make a DC 15 Constitution saving throw . On a failure, the creature contracts radiation sickness (see Maladies on page 281).

Creatures immune to poison damage, or who are wearing radiation shielded clothing, are not affected by irradiated areas.

Irradiated, Severe (+4)

Nuclear meltdowns, quasars, and breached antimatter engines create even more intense radiation.

Creatures immune to poison damage, or who are wearing radiation shielded clothing, treat severely irradiated areas as irradiated areas.

World Actions

Radiation Poisoning. A creature which begins its turn in a severely irradiated area must make a DC 15 Constitution saving throw . On a failure, the creature takes 28 (8d8) poison damage and is poisoned until medically treated using an anti-rad drug or similar effect. Additionally, the creature contracts radiation sickness .

High Gravity (+2)

The ranges of ranged weapons are halved, as are all jump distances. When a creature makes its first attack in a round using a weapon that does not have the dual-wielding property, it makes a DC 12 Athletics check or subtracts 1d4 from its attack rolls for 1 round. Falling damage is treated as twice the distance in the area and there is no maximum amount of damage that can be taken from a fall. For every hour spent in the area, a creature not acclimated to it makes a Constitution saving throw (DC 8 + the number of hours spent in the area) or gain a level of fatigue (maximum 4 levels of fatigue).

Low Gravity (-1)

The ranges of ranged weapons are doubled, as are all jump distances. Falling damage is treated as half the distance in the area. In addition, damage from bludgeoning weapons is reduced by half.

Zero Gravity (+1)

While artificial gravity is a staple of most sci-fi settings, many settings stick to a more realistic depiction of weightless movement, using the environment around them as useful handholds and points to kick off from.

Creatures treat zero-G environments as difficult terrain so long as they are adjacent to a solid surface. Creatures may move into areas without an adjacent surface in this way, but if they end their turn with no adjacent surface they begin drifting and their movement speed is reduced to 0. Drifting creatures can throw any item on their person that weighs at least 5 pounds or use any propellant item (such as a cytospray, construction foam, spray adhesive, spray paint, or zero-friction lubricant) to move up to 10 feet as a bonus action.

Spacesuits. Creatures with the spacefaring feature or creatures wearing armor with the spacefaring feature ignore the difficult terrain caused by zero-G environments and are immune to drifting. Creatures with a natural climb speed also ignore the difficult terrain caused by zero-G environments, but are not immune to drifting.

Thick/Thin Atmosphere (+1)

While both thick and thin atmospheres are very dissimilar, their effects on creatures are not so different. Creatures can breathe in these atmospheres, but it is harder. Every hour, a creature in a thick or thin atmosphere must make a DC 12 Constitution saving throw or gain one level of fatigue .

Vacuum (+2)

An area of vacuum has no air, so creatures that need to breathe must use another source of air or begin to suffocate once they cannot hold their breath. In addition, the area carries no sound, so hearing-based checks made to perceive automatically fail.

Spacesuits. Armor with the spacefaring classification protects its wearer from hard vacuum, but even the smallest puncture in a suit can be deadly. As such, most spacefaring suits are equipped with self-sealing technology to protect against small punctures, tears, and fractures, but a critical hit renders a spacefaring suit damaged. When a creature’s spacefaring suit is damaged, roll 1d6 at the start of each of the creature’s turns. On a roll of 6 the suit is no longer able to provide protection from hard vacuum. A second critical hit before the damage is patched or repaired completely breaks the suit, rendering it broken and ineffective.

Vacuum Breach (+3)

When there is a pressure differential between two areas, such as a hull breach or an open door leading to the surface of an airless rock, the atmosphere rushes out in an attempt to level out the differential. This takes the form of a rushing wind.

Ranged weapon attacks and Perception checks that rely on hearing have disadvantage in high winds. In addition, the rushing air extinguishes any open flames, disperses fogs and smoke, and forces any flying creature to land before the end of its turn or fall.

World Actions

Rushing Winds. Each creature in the area must make a DC 14 Strength saving throw or be pulled 20 feet in the direction of the winds. A creature with one or more spare limbs (at the Narrator’s discretion) may use a bonus action to grab on or anchor itself, which allows it to make the saving throw with advantage .

Hard Vacuum & Lingering Injuries

The vacuum of space is also utterly chilling or scorching hot, depending on whether a creature is in sunlight or shadow. The vacuum deals 11 (3d6) cold or fire damage to a creature at the start of each of its turns in the area. If cold damage (but not fire damage) from a vacuum drops a creature to 0 hit points or happens after they are already at 0 hit points, they suffer a lingering injury. The Narrator can dictate an injury and its effects or determine it by rolling a d4: 1—blindness, 2—burns, 3—loss of taste, 4—frostbite (see Table: Frostbite).

After a day of rest, the affected creature may make a DC15 Constitution saving throw , made with advantage if it has received medical attention since the exposure. On a success, the creature heals; on a failure, the affliction persists. The creature may make further Constitution saving throws after each subsequent day, but the DC increases by 1. If the creature fails three of these saves, the injury becomes permanent.

Zirkon Crystals (+2)

Zirkon is a rare natural crystal which dampens psionic energy. The cost to manifest psionic powers in an area containing zirkon crystals is doubled. Additionally, psionic powers of level III or less cannot penetrate solid zirkon barriers (see Objects).