Conditions alter a creature's capabilities in a variety of ways and can arise as a result of a spell, a class feature, a monster's attack, or other effect. Most conditions, such as blinded, are impairments, but a few, such as invisible, can be advantageous.

A condition lasts either for a duration specified by the effect that imposed the condition or until the condition is countered (the Prone condition is countered by standing up, for example).

If multiple effects impose the same condition on you, each instance of the condition has its own duration, but the condition’s effects don’t get worse. Either you have a condition or you don’t. The Exhaustion condition is an exception; its effects get worse if you have the condition and receive it again.

The following definitions specify what happens to a creature while it is subjected to a condition.

While you have the Blinded condition, you experience the following effects.

Can’t See. You can’t see and automatically fail any ability check that requires sight.

Attacks Affected. Attack rolls against you have Advantage, and your attack rolls have Disadvantage.

While you have the Charmed condition, you experience the following effects.

Can’t Harm the Charmer. You can’t attack the charmer or target the charmer with damaging abilities or magical effects.

Social Advantage. The charmer has Advantage on any ability check to interact with you socially.

While you have the Deafened condition, you experience the following effect.

Can’t Hear. You can’t hear and automatically fail any ability check that requires hearing.

While you have the Exhaustion condition, you experience the following effects.

Anything that causes Exhaustion, can cause a level of Strife instead.

Exhaustion Levels. This condition is cumulative. Each time you receive it, you gain 1 Exhaustion level. You die if your Exhaustion level is 6.

D20 Tests Affected. When you make D20 Tests, the roll is reduced by 2 times your Exhaustion level.

Speed Reduced. Your Speed is reduced by a number of feet equal to 5 times your Exhaustion level.

Removing Exhaustion Levels. Finishing a Long Rest removes 1 of your Exhaustion levels. When your Exhaustion level reaches 0, the condition ends.

While you have the Frightened condition, you experience the following effects.

Ability Checks and Attacks Affected. You have Disadvantage on ability checks and attack rolls while the source of fear is within line of sight.

Can’t Approach. You can’t willingly move closer to the source of fear.

While you have the Grappled condition, you experience the following effects.

Speed 0. Your Speed is 0 and can’t increase.

Attacks Affected. You have Disadvantage on attack rolls against any target other than the grappler.

Movable. The grappler can drag or carry you when it moves, but every foot of movement costs it 1 extra foot unless you are Tiny or two or more sizes smaller than it.

When you have the Hidden condition, you experience the following effects. When you’re Hidden from a creature, they don’t know your location. If you are no longer in a Concealable Location or benefiting from another condition that allows you to take the Hide action, you immediately lose the Hidden condition.

Concealed. You can’t be affected by any effect that requires its target to be seen if you are Hidden from the effect’s creator.

Surprise. If you are Hidden from all enemies when you roll Initiative, you have Advantage on the roll.

Combat Advantage. Attack rolls against a Hidden opponent have Disadvantage, and a Hidden opponent’s attack rolls have Advantage.

Detectable Actions. If you make an attack or take some other loud or overt action (such as talking louder than a whisper, kicking open a door, or casting a spell with a Verbal component), other creatures will pinpoint your current location, allowing them to, for example, aim attacks at you (although you would still benefit from your Combat Advantage). In addition, taking a detectable action allows any observer you’re currently Hidden from to make a Wisdom (Perception) check to spot you (removing the benefits of the Hidden condition). Observers can use a reaction to gain advantage on this check.

Leaving Concealment. If you are no longer in a Concealable Location or benefiting from another condition or effect that allows you to take the Hide action, you lose the Hidden condition. If this happens on your turn in combat, you lose the Hidden condition at the end of your turn. (If, after being revealed, you take the Hide action again, you can immediately regain the Hidden condition after losing it, but observers will remain aware of where they last saw or detected you.) If you Ready an action triggered by something that would reveal your location, you lose the Hidden condition at the end of your Readied action. (For example, you could Hide behind a closed door and then stab someone opening the door, while still gaining the benefits of Hidden on your attack.)

Source: https://thealexandrian.net/wordpress/52099/roleplaying-games/dd-2024-hiding-invisibility

While you have the Incapacitated condition, you experience the following effects.

Inactive. You can’t take any action, Bonus Action, or Reaction.

No Concentration. Your Concentration is broken.

Speechless. You can’t speak.

Surprised. If you’re Incapacitated when you roll Initiative, you have Disadvantage on the roll.

When you have the Invisible condition, you experience the following effects.

You cannot be seen. Any equipment you’re carrying or wearing is also invisible.

You can take the Hide action without needing to be in a Concealable Position.

You gain Advantage on checks that would benefit from not being seen, including Dexterity (Stealth) checks.

Attack rolls against you have Disadvantage, and your attack rolls have Advantage.

You do not gain the benefits of Invisible against any creature who can somehow see you. (For example, due to a See Invisibility)

Source: https://thealexandrian.net/wordpress/52099/roleplaying-games/dd-2024-hiding-invisibility

While you have the Paralyzed condition, you experience the following effects.

Inactive. You can’t take any action, Bonus Action, or Reaction.

No Concentration. Your Concentration is broken.

Speechless. You can’t speak.

Surprised. If you’re Paralyzed when you roll Initiative, you have Disadvantage on the roll.

Speed 0. Your Speed is 0 and can’t increase.

Saving Throws Affected. You automatically fail Strength and Dexterity saving throws.

Attacks Affected. Attack rolls against you have Advantage.

Automatic Critical Hits. Any attack roll that hits you is a Critical Hit if the attacker is within 5 feet of you.

While you have the Petrified condition, you experience the following effects.

Turned to Inanimate Substance. You are transformed, along with any nonmagical objects you are wearing and carrying, into a solid inanimate substance (usually stone). Your weight increases by a factor of ten, and you cease aging.

Incapacitated. You have the Incapacitated condition.

Speed 0. Your Speed is 0 and can’t increase.

Attacks Affected. Attack rolls against you have Advantage.

Saving Throws Affected. You automatically fail Strength and Dexterity saving throws.

Resist Damage. You have Resistance to all damage.

Poison Immunity. You have Immunity to the Poisoned condition.

While you have the Poisoned condition, you experience the following effect.

Ability Checks and Attacks Affected. You have Disadvantage on attack rolls and ability checks.

While you have the Prone condition, you experience the following effects.

Restricted Movement. Your only movement options are to crawl or to spend an amount of movement equal to half your Speed (round down) to right yourself and thereby end the condition. If your Speed is 0, you can’t right yourself.

(While you’re crawling, each foot of movement costs 1 extra foot (2 extra feet in Difficult Terrain).

Attacks Affected. You have Disadvantage on attack rolls. An attack roll against you has Advantage if the attacker is within 5 feet of you. Otherwise, that attack roll has Disadvantage.

While you have the Restrained condition, you experience the following effects.

Speed 0. Your Speed is 0 and can’t increase.

Attacks Affected. Attack rolls against you have Advantage, and your attack rolls have Disadvantage.

Saving Throws Affected. You have Disadvantage on Dexterity saving throws.

Intense study of potent arcana, truly rigorous intellectual challenges, and psychically demanding magics can increase one’s strife. Strife represents corruption, despair, fear, loss of resolve, and other mental factors which gradually undo a creature’s very soul. A creature which reaches the 7th level of the strife track suffers a special, permanent effect, which is either randomly selected or decided by the DM. This might involve the creature shutting down completely, or being impacted in such a way that it is forever changed.

Anything that could cause Strife can cause a level of Exhaustion instead.

Strife Level Effects

1. Disadvantage on Intelligence, Wisdom, and Charisma checks
2. Disadvantage on concentration checks
3. Can only take a bonus action or action each turn (not both)
4. Disadvantage on attack rolls and saving throws using Intelligence, Wisdom, and Charisma
5. Suffer the effects of a randomly determined short-term mental stress effect.
6. Cannot cast spells (but can cast cantrips)
7. Suffer the effects of a randomly determined long-term mental stress effect.

Source: Level Up Adventurers Guide v2a.pdf

While you have the Stunned condition, you experience the following effects.

Inactive. You can’t take any action, Bonus Action, or Reaction.

No Concentration. Your Concentration is broken.

Speechless. You can’t speak.

Surprised. If you’re Stunned when you roll Initiative, you have Disadvantage on the roll.

Saving Throws Affected. You automatically fail Strength and Dexterity saving throws.

Attacks Affected. Attack rolls against you have Advantage.

A character can also choose to break this effect at the start of their turn by taking 4 (1d8) psychic damage per two character levels.

Source: Lazy DM’s Companion (damage to break stun)

While you have the Unconscious condition, you experience the following effects.

Inert. You have the Incapacitated and Prone conditions, and you drop whatever you’re holding.

When this condition ends, you remain Prone.

Inactive. You can’t take any action, Bonus Action, or Reaction.

No Concentration. Your Concentration is broken.

Speechless. You can’t speak.

Surprised. If you’re Unconscious when you roll Initiative, you have Disadvantage on the roll.

Speed 0. Your Speed is 0 and can’t increase.

Restricted Movement. Your only movement options are to crawl or to spend an amount of movement equal to half your Speed (round down) to right yourself and thereby end the condition. If your Speed is 0, you can’t right yourself.

While you’re crawling, each foot of movement costs 1 extra foot (2 extra feet in Difficult Terrain).

Attacks Affected. Attack rolls against you have Advantage.

Saving Throws Affected. You automatically fail Strength and Dexterity saving throws.

Automatic Critical Hits. Any attack roll that hits you is a Critical Hit if the attacker is within 5 feet of you.

Unaware. You’re unaware of your surroundings.

Source
https://www.dndbeyond.com/sources/dnd/free-rules/playing-the-game#Conditions