Robot, Bastion

Family: Robot

Huge construct (robot), lawful neutral or evil depending on patron

Armor Class 22 (noqual enameled skymetal body)
Hit Points 284 (21d12 + 147) plus 90 hp force field
Speed 40 ft.

18 (+4) 24 (+7) 24 (+7) 18 (+4) 11 (+0) 11 (+0)

Saving Throws Dex +10
Skills Perception +12
Damage Resistances bludgeoning, piercing, and slashing from nonmagical weapons that aren’t adamantine
Damage Immunities necrotic, poison, psychic
Damage Vulnerabilities lightning
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 120 ft., passive Perception 10
Languages Common (an ancient dialect, but still understandable)
Challenge 18 (20,000 XP)


  • Empowered Attacks. A bastion robot’s melee attacks are treated as magical for the purpose of bypassing resistance and immunity to nonmagical weapons.
  • Exceptional Senses. A bastion robot has advantage on Wisdom (Perception) checks that rely on sight or sound and has double proficiency bonus in the Perception skill as it constantly scans its surroundings for danger.
  • Immunity to Magic. A bastion robot is immune to and absorbs any spell or spell-like ability. In addition, certain spells and effects function differently against it, as detailed below. Magical lightning damage slows Bastion until the end of its next round, with no saving throw. If is is hasted, magical lightning attacks instead negates the haste effect. Dispel magic negates its Impeded Magic ability for 1d4 rounds.
  • Impeded Magic. A spellcaster within 60 feet of a bastion robot must succeed at a Constitution ability check (DC 15 + the level of the spell being cast) to successfully cast a spell— if this check fails, a bastion robot absorbs the spell and the caster loses the spell.
  • Overwhelming Nanite Surge (3/day). If a bastion robot fails a saving throw, he can choose to succeed.
  • Quantum Force Field. A bastion robot is sheathed in a thin layer of shimmering quantum energy that grants it 90 temporary hit points. All damage dealt to it with an active force field is reduced from these hit points first. If the force field is active, the robot is immune to critical hits; force attacks and loses its weakness to lightning damage. The force field has an effective regeneration of 90, but once reduced to 0; the force field shuts down and does not reactivate until a long rest is completed.
  • Spell Absorption. Whenever a bastion robot absorbs a spell, it heals 5 points of damage per spell level. Healing more than its normal hit point maximum grants it temporary hit points. These hit points stack with its Quantum Force Field if it is still active. Absorbing a spell gives the robot the benefits of the haste spell for 1 round per spell level absorbed.
  • Spell Sunder. A creature struck by a bastion robot’s Force Slam attack is targeted by dispel magic. The bastion robot absorbs any spells so sundered.


  • Multiattack. The bastion robot makes two Force Slam attacks against two opponents (so four attacks but not against the same opponent). He also uses gravitywave if available.
  • Force Slam. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage plus 10 (3d6) force damage, and the target is grappled (escape DC 19). Bastion can grapple up to four targets. When Bastion moves, all creatures he is grappling move with him. On a natural 20, the target takes an extra 14 bludgeoning damage if it’s a construct. If a construct has 25 hit points or fewer after taking this damage, it is destroyed. Additionally, a target is also targeted by thespell sunder trait.
  • Gravitywave (Recharges 5-6). Spinning up his shoulder mounted gravity cannons Bastion unleashes a barrage of graviton beams. The barrage targets all creatures within 30 feet of it and each must succeed on a DC 24 Constitution saving throw, taking 45 (10d8) force damage on a failed save, or half as much damage on a successful one. In addition, targets are subjected to a reverse gravity effect (as the spell) regardless of whether the target made or failed the saving throw.


A bastion robot can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Bastion regains spent legendary actions at the start of its turn.

  • Crush. One creature that the bastion robot is grappling is crushed for 20 (3d10 + 4) bludgeoning damage.
  • Fling. The bastion robot releases one creature it is grappling by flinging the creature up to 60 feet away from it, in a direction of his choice. If the flung creature meets a solid surface, such as a wall or floor, the creature takes 1d6 bludgeoning damage for every 10 feet it was flung.
  • Gravitywave (Costs 3 Actions). The bastion robot recharges Gravitywave and uses it.


A bastion robot typically resides in a fallen spacecraft or massive edifice of lost technology, often setting itself up as the head of a techno-cult of a mechanical goddess. It sits at the nerve center of those ancient ruins surrounded by magical divination screens (monitors) which he observes and directs the faithful. If challenged without first destroying its mechanical minions, every construct or servant nearby will arrive to aid the bastion within 1d4 rounds.

On initiative count 20 (losing initiative ties), the bastion robot takes a lair action to cause one of the following effects; the robot can’t use the same effect two rounds in a row:

  • Automated Laz-Cannons pop out of cunningly hidden recesses in the roof and spray the area with gunfire. They are superhumanly accurate and only hit enemy creatures. Each creature in the room must make a DC 15 Dexterity save or take 12 (4d6) radiant damage.
  • The room is flooded with noqual infused gas. All spellcasters must make a DC 15 Constitution saving throw or lose a randomly memorized spell (or a random spell slot for spontaneous casters like sorcerers).
  • One creature the bastion robot can see within 60 feet of it must succeed on a DC 15 Charisma saving throw or be banished to the Matrix – a digital plane – a different plane of existence UNITY has programmed into being. To escape, the creature must use its action to make a DC 15 Charisma ability check. If the creature wins, it escapes the digital plane. Otherwise, the effect ends on initiative count 20 on the next round. When the effect ends, the creature reappears in the space it left or in the nearest unoccupied space if that one is occupied.


This four-armed gleaming, green-enameled humanoid shaped machine was designed and built to hunt and kill magic-users. A bastion robot typically acts as the proxy of a machine goddess, master of a cult of sentient constructs and allied living creatures. They protect the domain of their mechanical patron and coordinate their cultists to destroy purely magical creatures and organizations and preserve the mastery of technology and technomagical hybrids.

Section 15: Copyright Notice

Mechanical Monsters (5E) © 2023, Legendary Games; Authors: Jason Nelson, Miguel Colon, Robert J. Grady, Nicholas Hite, Matt Kimmel, Michael Mifsud, James-Levi Cooke, Dan Dillon, Mike Myler, Ismael Alvarez, Jeff Lee, John Lynch.

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