This section offers a selection of common monster powers you can apply to any quick-build monster to give them a stronger mechanical flavor, make them more tactically interesting, or reinforce their behavior in the story of your game.

The monster has Advantage on melee attack rolls against any creature that doesn’t have all its HP.

A melee weapon deals one extra die of its damage when the creature hits with it.

If the monster moves at least [1/2 its walking speed] feet straight toward a target and then hits it with a melee attack on the same turn, the target takes an extra [1d4 + STR] bludgeoning damage. If the target is a creature, it must succeed on a DC [8 + STR + PB] STR save or be knocked prone.

When the creature hits with any weapon, the weapon deals an extra # [acid, cold, fire, lightning, or thunder] damage.

The monster has advantage on attack rolls against any creature grappled by it.

The creature’s weapon attacks are magical.

The monster has advantage on attack rolls against a creature if at least one of the monster’s allies is within 5 feet of the creature and the ally isn’t incapacitated.

If the monster moves at least [1/2 its walking speed] feet straight toward a creature and then hits it with a melee attack on the same turn, that target must succeed on a DC [8 + STR + PB] STR save or be knocked prone. If the target is prone, the monster can make one melee attack against it as a bonus action.

The creature deals double damage to objects and structures.

Whenever the creature is subjected to [acid, cold, fire, lightning, or thunder] damage, it takes no damage and instead regains HP equal to the [acid, cold, fire, lightning, or thunder] damage dealt.

A creature that touches the monster or hits it with a melee attack while within 5 feet of it takes # [acid, cold, fire, lightning, or thunder] damage.

If the creature is subjected to an effect that allows it to make a DEX save to take only half damage, the creature instead takes no damage if it succeeds on the save, and only half damage if it fails.

The creature doesn’t provoke opportunity attacks when it flies out of an enemy’s reach.

Any critical hit against the creature becomes a normal hit.

The creature is immune to any spell or effect that would alter its form.

The creature is immune to any effect that would sense its emotions or read its thoughts, as well as any divination spell or effect, such as scrying or detecting its location, that it refuses. WIS (Insight) checks made to ascertain the creature’s intentions or sincerity have disadvantage.

While the monster is conscious, each friendly creature within 10 feet of it, including itself, is resistant to the charmed and frightened conditions.

The creature has advantage on saves against spells and other magical effects.

The creature has # of heads and is resistant to the blinded, charmed, deafened, frightened, stunned, and unconscious conditions.

If the creature starts its turn afflicted by an ongoing effect that allows for a repeated save to end the effect, such as the hold spell or the poison from an ettercap’s Bite, the creature can make the save at the start of the turn instead of the end and has advantage on the save.

A creature that starts its turn within 5 feet of the monster must succeed on a DC [8 + CON + PB] CON save or be poisoned until the start of its next turn. On a success, the creature is immune to the monster’s Stench for 24 hours.

The creature can move through a space as narrow as 1 inch wide without squeezing.

The creature can burrow through non magical, unworked earth and stone. While doing so, the creature doesn’t disturb the material through which it moves.

The creature can move across icy surfaces without needing to make an ability check. In addition, difficult terrain composed of ice or snow doesn’t cost extra movement.

The monster can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

With a 10-foot running start, the creature can long jump up to 25 feet.

The creature can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

The creature’s long jump is up to [10 below walking speed] feet and its high jump is up to [half of long jump distance] feet, with or without a running start.

The creature ignores movement restrictions caused by webbing.

Difficult terrain composed of non magical plants doesn’t cost the creature extra movement. In addition, the creature can pass through non magical plants without being slowed by them and without taking damage from them if they have thorns, spines, or a similar hazard.

The creature can breathe air and water.

Magical darkness doesn’t impede the creature’s darkvision.

The creature can’t use its keensense while deafened.

The creature’s Stealth is [base + 5] while in [type of] terrain.

The creature can see 60 feet into the Ethereal Plane when it is on the Material Plane, and vice versa.

While the creature remains motionless, it is indistinguishable from a relevant object or its surroundings.

The creature’s Perception is [base + 5] when perceiving by [sense].

The creature sheds bright light in a 30-foot radius and dim light for an additional 30 feet.

The creature can pinpoint, by scent, the location of ferrous metal within 30 feet of it.

The monster can magically communicate simple ideas, emotions, and images telepathically with any creature within 100 feet of it that can understand a language.

The monster can mimic simple sounds it has heard, such as a person whispering, a baby crying, or an animal chittering. A creature that hears the sounds can tell they are imitations with a successful DC [10 + CHA] WIS (Insight) check.

The creature can communicate with Beasts as if they shared a language.

While in sunlight, the creature has disadvantage on attack rolls, and its Perception is [base − 5] when perceiving by sight.

While motionless, the creature’s Stealth is [base + 5], even when it is in plain sight.

The creature can pinpoint, by scent, the location of precious metals and stones, such as coins and gems, within 60 feet of it.

Any creature who moves within 10 feet of this creature or who starts their turn there takes CR damage of a type appropriate for this creature.

Reskin this aura to meet your needs based on the damage type. A fire elemental can radiate an aura of fire, while an undead might radiate necrotic damage. You can also describe this effect as a magical aura dealing force damage or a holy aura dealing radiant damage, or even have a many-armed creature wielding swords to create an aura of slashing damage.

This creature’s melee weapon attacks deal an extra CR damage of a type appropriate for the creature.

As with Damaging Aura, this trait can be customized for many types of creatures by choosing a thematic damage type. A warrior might wield a greatsword that deals extra fire or lightning damage as a boon bestowed by their god. A mini-boss undead could deal necrotic or cold damage to represent their innate supernatural power.

When attacking a target whose current hit points are below half their hit point maximum, this creature has Advantage on attack rolls and deals an extra CR damage when they hit.

This trait makes a monster extremely dangerous in a tough fight, and encourages the characters to use healing resources.

At the start of their turn, this creature can gain Advantage on all melee weapon attack rolls made during this turn, but attack rolls against them have Advantage until the start of their next turn.

In addition to providing a combat boost for a foe, this trait can help accelerate a fight that’s gone on long enough, by letting the characters hit the last remaining foes more often.

This creature has a +CR bonus to damage rolls, and scores a critical hit on an unmodified attack roll of 18–20.

This simple trait is a default you can use to increase the damage dealt by any monster.

When this creature hits a target with a ranged attack, allies of this creature who can see the target have Advantage on attack rolls against the target until the start of this creature’s next turn.

Let a monster apply pressure to a specific target with this power, especially if that target is wounded or in a vulnerable position. Make the foe’s action obvious, so that the players know to react to it and can help the targeted character survive the ensuing focused fire.

When this creature is reduced to 0 hit points, they drop Prone and are indistinguishable from a dead creature. At the start of their next turn, this creature stands up without using any movement and has 2 × CR hit points. They can then take their turn normally.

This trait can represent a clever combatant playing dead, a warrior with incredible resolve, or a creature such as an undead or an ooze who refuses to die.

At the start of this creature’s turn, they can attempt a saving throw against any effect on them that can be ended by a successful saving throw.

This power can protect vulnerable combatants and bosses from being shut down by spells. It can represent magical mastery, divine favor, luck, or a specific quality of the creature. As a variant, using this trait could require the foe to take 2 × CR damage if the new saving throw is successful, representing the exertion made to overcome the effect.

When this creature’s current hit points are below half their hit point maximum, the creature deals CR extra damage with each of their attacks.

This trait works best when given to a single important foe, and when you describe the monster’s refusal to surrender despite their many wounds. This lets the players know they can focus fire to finish the creature off, minimizing their damage potential.

This creature has Advantage on Dexterity (Stealth) checks.

Foes fighting in obscured areas or behind cover can benefit from this trait, which can represent natural camouflage or well-practiced skill.

Source: Lazy DM's Forge of Foes