5e Rules Reference

Unless marked Homebrew, the below rules are from the official 5e SRD.

Cover

Walls, trees, creatures, and other obstacles can provide cover during combat, making a target more difficult to harm. A target can benefit from cover only when an attack or other effect originates on the opposite side of the cover.
There are three degrees of cover. If a target is behind multiple sources of cover, only the most protective degree of cover applies; the degrees aren't added together. For example, if a target is behind a creature that gives half cover and a tree trunk that gives three-quarters cover, the target has three-quarters cover.
A target with half cover has a +2 bonus to AC and Dexterity saving throws. A target has half cover if an obstacle blocks at least half of its body. The obstacle might be a low wall, a large piece of furniture, a narrow tree trunk, or a creature, whether that creature is an enemy or a friend. Homebrew: creatures only get cover from other creatures that are the same size or larger.
A target with three-quarters cover has a +5 bonus to AC and Dexterity saving throws. A target has three-quarters cover if about three-quarters of it is covered by an obstacle. The obstacle might be a portcullis, an arrow slit, or a thick tree trunk.
A target with total cover can't be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle.

Visibility

The most fundamental tasks of adventuring--noticing danger, finding hidden objects, hitting an enemy in combat, and targeting a spell, to name just a few--rely heavily on a character's ability to see. Darkness and other effects that obscure vision can prove a significant hindrance.
A given area might be lightly or heavily obscured. In a lightly obscured area, such as dim light, patchy fog, or moderate foliage, creatures have disadvantage on Wisdom (Perception) checks that rely on sight.
A heavily obscured area--such as darkness, opaque fog, or dense foliage--blocks vision entirely. A creature effectively suffers from the blinded condition when trying to see something in that area.

Illumination

The presence or absence of light in an environment creates three categories of illumination: bright light, dim light, and darkness.
Bright light lets most creatures see normally. Even gloomy days provide bright light, as do torches, lanterns, fires, and other sources of illumination within a specific radius.
Dim light, also called shadows, creates a lightly obscured area. An area of dim light is usually a boundary between a source of bright light, such as a torch, and surrounding darkness. The soft light of twilight and dawn also counts as dim light. A particularly brilliant full moon might bathe the land in dim light.
Darkness creates a heavily obscured area. Characters face darkness outdoors at night (even most moonlit nights), within the confines of an unlit dungeon or a subterranean vault, or in an area of magical darkness.

Vision

Blindsight

A creature with blindsight can perceive its surroundings without relying on sight, within a specific radius. Creatures without eyes, such as oozes, and creatures with echolocation or heightened senses, such as bats and true dragons, have this sense.

Darkvision

Many creatures in fantasy gaming worlds, especially those that dwell underground, have darkvision. Within a specified range, a creature with darkvision can see in darkness as if the darkness were dim light, so areas of darkness are only lightly obscured as far as that creature is concerned. However, the creature can't discern color in darkness, only shades of gray.

Truesight

A creature with truesight can, out to a specific range, see in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceives the original form of a shapechanger or a creature that is transformed by magic.
Furthermore, the creature can see into the Ethereal Plane.

Sources of light

Torches, candles, and the Light and Daylight spells all last for an hour, while lamps and lanterns burn for 6 hours on a pint (1 silver piece) of oil.

Homebrew

If you drop (as opposed to set down) a lit torch or candle on the ground it has a 50% chance of being extinguished. A torch or candle that is extinguished by being dropped on the ground is destroyed and cannot be reignited.
Dropped lamps and lanterns have a 25% chance of being extinguished and spilling their remaining oil.

Conditions

Blinded

A blinded creature can't see and automatically fails any ability check that requires sight. Attack rolls against the creature have advantage, and the creature's attack rolls have disadvantage.

Charmed

A charmed creature can't attack the charmer or target the charmer with harmful abilities or magical effects. The charmer has advantage on any ability check to interact socially with the creature.

Deafened

A deafened creature can't hear and automatically fails any ability check that requires hearing.

Exhaustion

Some special abilities and environmental hazards, such as starvation and the long-term effects of freezing or scorching temperatures, can lead to a special condition called exhaustion. Exhaustion is measured in six levels. An effect can give a creature one or more levels of exhaustion, as specified in the effect's description.
Level Effect

1. Disadvantage on ability checks
2. Speed halved
3. Disadvantage on attack rolls and saving throws
4. Hit point maximum halved
5. Speed reduced to 0
6. Death Homebrew: Catatonic

If an already exhausted creature suffers another effect that causes exhaustion, its current level of exhaustion increases by the amount specified in the effect's description.
A creature suffers the effect of its current level of exhaustion as well as all lower levels. For example, a creature suffering level 2 exhaustion has its speed halved and has disadvantage on ability checks.
An effect that removes exhaustion reduces its level as specified in the effect's description, with all exhaustion effects ending if a creature's exhaustion level is reduced below 1.
Finishing a long rest reduces a creature's exhaustion level by 1, provided that the creature has also ingested some food and drink.

Homebrew

A character with six levels of exhaustion is catatonic but not dead: they are unconscious and can't be awoken.

Frightened

A frightened creature has disadvantage on ability checks and attack rolls while the source of its fear is within line of sight.
The creature can't willingly move closer to the source of its fear.

Grappled

A grappled creature's speed becomes 0, and it can't benefit from any bonus to its speed.
The condition ends if the grappler is incapacitated (see the condition).
The condition also ends if an effect removes the grappled creature from the reach of the grappler or grappling effect, such as when a creature is hurled away by the thunder-wave spell.

Incapacitated

An incapacitated creature can't take actions or reactions.

Invisible

An invisible creature is impossible to see without the aid of magic or a special sense. For the purpose of hiding, the creature is heavily obscured. The creature's location can be detected by any noise it makes or any tracks it leaves.
Attack rolls against the creature have disadvantage, and the creature's attack rolls have advantage.

Paralyzed

A paralyzed creature is incapacitated (see the condition) and can't move or speak.

The creature automatically fails Strength and Dexterity saving throws. Attack rolls against the creature have advantage.

Any attack that hits the creature is a critical hit if the attacker is within 5 feet of the creature.

Petrified

A petrified creature is transformed, along with any nonmagical object it is wearing or carrying, into a solid inanimate substance (usually stone). Its weight increases by a factor of ten, and it ceases aging.

The creature is incapacitated (see the condition), can't move or speak, and is unaware of its surroundings.

Attack rolls against the creature have advantage.

The creature automatically fails Strength and Dexterity saving throws.

The creature has resistance to all damage.
The creature is immune to poison and disease, although a poison or disease already in its system is suspended, not neutralized.

Poisoned

A poisoned creature has disadvantage on attack rolls and ability checks.

Prone

A prone creature's only movement option is to crawl, unless it stands up and thereby ends the condition.
The creature has disadvantage on attack rolls.
An attack roll against the creature has advantage if the attacker is within 5 feet of the creature. Otherwise, the attack roll has disadvantage.

Restrained

A restrained creature's speed becomes 0, and it can't benefit from any bonus to its speed.
Attack rolls against the creature have advantage, and the creature's attack rolls have disadvantage.
The creature has disadvantage on Dexterity saving throws.

Stunned

A stunned creature is incapacitated (see the condition), can't move, and can speak only falteringly. The creature automatically fails Strength and Dexterity saving throws. Attack rolls against the creature have advantage.

Unconscious

An unconscious creature is incapacitated (see the condition), can't move or speak, and is unaware of its surroundings The creature drops whatever it's holding and falls prone. The creature automatically fails Strength and Dexterity saving throws. Attack rolls against the creature have advantage. Any attack that hits the creature is a critical hit if the attacker is within 5 feet of the creature.

Size categories

Damage types

Fifth edition D&D has thirteen damage types:

Monster categories