Combat

There are times when words and diplomacy will fail, and the only thing that can save you is a quick and brutal battle. These are the basic, all important rules of how combat works.

The Order of Combat
A typical combat encounter is a clash between two sides, a flurry of weapon swings, feints, parries, footwork, and spellcasting. The game organizes the chaos of combat into a cycle of rounds and turns. A round represents about 6 seconds in the game world. During a round, each participant in a battle takes a turn. The order of turns is determined at the beginning of an encounter, when everyone rolls initiative. Once everyone has taken a turn, the fight continues to the next round if neither side has defeated the other.

Surprise
A band of adventurers sneaks up on a bandit camp, springing from the trees to attack them. A Bubble Slime slides down a dungeon passage, unnoticed by the adventurers until the slime engulfs one of them. In these situations, one side of the battle gains surprise over the other.

The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity(Stealth) checks of anyone hiding with the Passive Perception score of each creature on the opposing side. Any character or opponent that doesn't notice the threat is surprised at the start of an encounter.

If you're surprised, you can't move or take an action on your first turn of the combat, and you can't take a reaction until that turn ends. A member of a group can be surprised even If the other members aren't.

Initiative
Initiative determines the order of turns during combat. When combat starts, every participant rolls a d20, and adds their Dexterity score's modifier to determine their place in the initiative order. The DM makes one roll for an entire group of creatures, so each member of the opposing force acts at the same time.

The DM ranks the combatants in order from the one with the highest Initiative roll to the one with the lowest. This is the order in which they act during round. The initiative order remains the same from round to round. If a tie occurs, the DM decides the order among tied DM-controlled opponents, and players decide the order among their tied characters. The DM can decide the order if a tie is between an opponent and a player character. Optionally, the DM can have tied characters and opponents roll a d20 to determine the order, highest roll going first.

Your Turn
On your turn you can move a distance up to your speed and take one action. You decide whether to move first or take your action. Your speed - sometimes called your walking speed - is noted on your Character Sheet.

The most common actions you can take are described a little bit later in this page. Many class features and other abilities provide additional options for your action. Movement rules are also described further on.

You can forego all moving, taking an action, or doing anything at all on your turn. If you can't decide what to do on your turn, consider taking the Dodge or Ready actions, as described in 'Actions in Combat' further below.

Bonus Actions
Various class features, spells, and other abilities let you take an additional action on your turn called a Bonus Action. The Cunning Action feature, for instance, allows a rogue to take a bonus action. You can take a bonus action only when a special ability, spell, or other feature of the game states that you can do something as a bonus action. You otherwise don't have a bonus action to take.

You can only make one bonus action on your turn, so you must choose which bonus action to use if you have more than one available.

You choose when to take a bonus action on your turn, unless the bonus action's timing is specified, and anything that deprives you of your abilities to take actions also prevents you from taking a bonus actions.

Other Activity on Your Turn
Your turn can include a variety of flourishes that require neither your action nor your move.

You can communicate however you are able, through brief utterances and gestures, as you take your turn.

You can also interact with one object or feature of the environment for free, during either your move or your action. For example, you could open a door during your move as you stride toward a foe, or you could draw your weapon as part of the same action as your attack.

If you want to interact with a second object, you need to use your action. Some magic items and other special objects always require an action to use, as stated in their descriptions.

The DM might require you to use an action for any of these activities when it needs special care of when it presents an unusual obstacle. For instance, the DM could reasonably expect you to use an action to open a stuck door or turn a crank to lower a drawbridge.

Reactions
Certain special abilities, spells, and situations allow you to take a special action called a reaction. A reaction is an instant response to a trigger of some kind, which can occur on your turn or someone else's. The opportunity attack, described later in this page, is the most common type of reaction.

When you take a reaction, you can't take another one until the start of your next turn. If the reaction interrupts another creature's turn, that creature can continue its turn right after the reaction.

Movement and Position
In combat, characters and opponents are in constant move, often using movement and position to gain the upper hand.

On your turn, you can move a distance up to your speed. You can use as much or as little of your speed as you like on your turn, following the rules here.

Your movement can include jumping, climbing and swimming. These different modes of movement can be combined with walking, or they can constitute your entire move. However you're moving, you deduct the distance of each part of your move from your speed until it is used up or until you are done moving.

The 'Special Types of Movement' section on the Adventuring page gives the particulars for jumping, climbing, and swimming.

Breaking Up Your Move
You can break up your movement on your turn, using some of your speed before and after your action. For example, if you have a speed of 30 feet, you can move 10 feet, take your action, and then move 20 feet.

Moving Between Attacks
If you take an action that includes more than one weapon attack, you can break up your movement even further by moving between those attacks. For example, a fighter who can make two attacks with the Extra Attack feature and who has a speed of 25 feet could move 10 feet, make an attack, move 15 feet, and then attack again.

Using Different Speeds
If you have more than one speed, such as your walking speed and flying speed, you can switch back and forth between your speeds during your move. Whenever you switch, subtract the distance you've already moved from the new speed. The result determines how much farther you can move. If the result is 0 or less, you can't use the new speed during the encounter.

For example, if you have a speed of 30 feet and a flying speed of 60 because a wizard cast the Fly spell on you, you could fly 20 feet, then walk 10 feet, then and then leap into the air to fly 30 feet more.

Difficult Terrain
Combat rarely takes place in bare rooms or on featureless plains. Boulder-strewn caverns, briar-choked forests, treacherous staircases - the setting of a typical fight contains difficult terrain.

Every foot of movement in difficult terrain costs 1 extra foot. This rule is true even if multiple things in a space count as difficult terrain.

Low furniture, rubble, undergrowth, steep stairs, snow, and shallow bogs are examples of difficult terrain. The space of another creature, whether hostile or not, also counts as difficult terrain.

Being Prone
Combatants often find themselves lying on the ground, either because they are knocked down or because they throw themselves down. In the game they are prone, a condition described on the Conditions page in the Handbook.

You can drop prone without using any of your speed. Standing up takes more effort: doing so costs an amount equal to half your speed. For example, if your speed is 30 feet, you must spend 15 feet of movement to stand up. You can't stand up if you don't have enough movement left or if your speed is 0.

To move while prone, you must crawl or use magic such as teleportation. Every foot of movement while crawling costs 1 extra foot. Crawling 1 foot in difficult terrain, therefore, costs 3 feet of movement.

Moving Around Other Creatures
You can move through a nonhostile creature's space. In contrast, you can move through a hostile creature's space only if the creature is at least two sizes larger or smaller than you. Remember that another creature's space is difficult terrain for you.

Whether a creature is a friend or an enemy, you can't willingly end your move in its space.

If you leave a hostile creature's reach during your move, you provoke an Opportunity Attack, as explained later on this page.

Flying Movement
Flying creatures enjoy many benefits of mobility, but they must also deal with the danger of falling. If a flying creature is knocked prone, has its speed reduced to 0, or is otherwise deprived of the ability to move, the creature falls, unless it has the ability to hover, or it is being held aloft by magic, such as the Fly spell.

Creature Size
Each creature takes up a different amount of space. The Size Categories table shows how much space a creature of a particular size controls in combat. Objects sometimes use the same size categories.

Space
A creature's space is the area in feet that it effectively controls in combat, not an expression of its physical dimensions. A typical medium creature isn't 5 feet wide, for example, but it does control a space that wide. If a medium Hobgoblin stands in a 5-foot wide doorway, other creatures can't get through unless the Hobgoblin lets them.

A creature's space also reflects the area it needs to fight effectively. For that reason, there's a limit to the number of creatures that can surround another creature in combat. Assuming medium combatants, eight creatures can fit in a 5-foot radius around another one.

Because larger creatures take up more space, fewer of them can surround a creature. If five large creatures crowd around a medium or smaller one, there's little room for anyone else. In contrast, as many as 20 medium creatures can surround a gargantuan one.

Squeezing Into a Smaller Space
A creature can squeeze through a space that is large enough for a creature one size smaller than it. Thus, a large creature can squeeze through a passage that's only 5 feet wide. While squeezing through a space, a creature must spend 1 extra foot for every foot it moves there, and it has disadvantage on attack rolls and Dexterity saving throws. Attack rolls against the creature have advantage while it is in the smaller space.

Actions in Combat
When you take your action on your turn, you can take one of the actions presented here, an action you gained from your class or a special feature, or an action that you improvise. Many creatures have action features of their own in their stat blocks.

When you describe an action not detailed elsewhere in the rules, the Dungeon Master tells you whether that action is possible and what kind of roll you need to make, if any, to determine success or failure.

Attack
The most common action to take in combat is the Attack action, whether you are swinging a sword, firing an arrow from a bow, or brawling with your fists.

With this action, you make one melee or ranged attack. See the 'Making an Attack' section of this page for the rules that govern making an attack.

Certain features, such as the Extra Attack feature of the Fighter, allow you to make more than one attack with this action.

Cast a Spell
Spellcasters such as Wizards and Clerics, as well as many creatures, have access to spells, and can use them to great effect in combat. Each spell has a casting time, which specifies whether the caster must use an action, a reaction, minutes, or even hours to cast the spell. Casting a spell is, therefore, not necessarily an action. Most spells do have a casting time of 1 action, so a spellcaster often uses his or her action in combat to cast a spell. See the page 'Spellcasting' for further rules on spellcasting.

Dash
When you take the Dash action, you gain extra movement for the current turn. The increase equals your speed, after applying any modifiers. With a speed of 30 feet, for example, you can move up to 60 feet on your turn if you Dash.

Any increase or decrease to your speed changes this additional movement by the same amount. if your speed of 30 feet is reduced to 15 feet, for instance, you can move up to 30 feet this turn if you Dash.

Disengage
If you take the Disengage action, your movement doesn't provoke opportunity attacks for the rest of the turn.

Dodge
When you take the Dodge action, you focus entirely on avoiding attacks. Until the start of your next turn, any attack roll made against you has disadvantage if you can see the attacker, and you make Dexterity saving throws with advantage. You lose this benefit if you are incapacitated or if your speed drops to 0.

Help
You can lend your aid to another creature in the completion of a task. When you take the Help action, the creature you aid gains advantage on the next ability check it makes to perform the task you are helping with, provided that it makes the check before the start of your next turn.

Alternatively, you can aid a friendly creature in attacking a creature within 5 feet of you. You feint, distract the target, or in some other way team up to make your ally's attack more effective. If your ally attacks the target before your next turn, the first attack roll is made with advantage.

Hide
When you take the Hide action, you make a Dexterity (Stealth) check in an attempt to hide, as if using the Stealth skill, using your Dexterity (Stealth) check against every creature's Passive Perception score. If you succeed, you gain certain benefits, as described in the 'Unseen Attackers and Targets' section later on this page.

Ready
Sometimes you want to get the jump on a foe or wait for a particular circumstance before you act. To do so, you can take the Ready action on your turn so that you can act later in the round using your reaction.

First, you decide what perceivable circumstance will trigger your reaction. Then, you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it. Examples include "If the cultist steps on the trapdoor, I'll pull the lever that opens it," and "If the goblin steps next to me, I move away!"

When the trigger occurs, you can either take your action right after the trigger finishes or ignore the trigger. Remember that you can take only one reaction per round.

When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell's magic requires Concentration (explained on the Spellcasting page). If your concentration is broken, the spell dissipates without taking effect. For instance, if you are concentrating on the Web spell and ready Magic Missile, your Web spell ends, and if you take damage before you release Magic Missile with your reaction, your concentration might be broken.

Search
When you take the Search action, you devote your attention to finding something. Depending on the nature of your search, the Dungeon Master might have you make a Wisdom (Perception) check or an Intelligence (Investigation) check.

Use an Object
You normally interact with an object while doing something else, such as when you draw a sword as part of an attack. When an object requires your action for its use, you take the Use an Object action. This action is also useful if you want to interact with more than one object on your turn.

Making an Attack
Whether you're striking with a melee weapon, firing a weapon at range, or making an attack roll as part of a spell, an attack has a simple structure If there's ever any question whether something you're doing counts as an attack, the rule is simple: if you're making an attack roll, you're making an attack.
 * 1) Choose a target. Pick a target within your attack's range: a creature, an object, or a location.
 * 2) Determine modifiers. The Dungeon Master determines whether the target has cover and whether you have advantage or disadvantage against the target.  In addition, spells, special effects, and other abilities can apply penalties or bonuses to your attack roll.
 * 3) Resolve the attack. You make the attack roll.  On a hit, you roll damage, unless the particular attack has rules that specify otherwise.  Some attacks cause special effects in addition to or instead of damage.

Attack Rolls
When you make an attack, your attack roll determines whether the attack hits or misses. To make an attack roll, roll a d20 and add the appropriate modifiers. If the total of the roll plus modifiers equals or exceeds the target's Armor Class(AC), the attack hits. The AC of a character is determined at character creation, whereas the AC of a creature is in its stat block.

Modifiers to the Roll
When a character makes an attack roll, the two most common modifiers to the roll are an ability modifier and the character's proficiency bonus. When a creature makes an attack roll, it uses whatever modifier is provided in its stat block.

'''Ability modifier. '''The ability modifier used for a melee weapon attack is Strength, and the ability modifier used for a ranged weapon attack is Dexterity. Weapons that have the Finesse or Thrown property break this rule.

Some spells also require an attack roll. The ability modifier used for a spell attack depends on the spellcasting ability of the spellcaster, as explained on the Spellcasting page.

'''Proficiency bonus. '''You add your proficiency bonus to your attack roll when you attack using a weapon with which you have proficiency, as well as when you attack with a spell.

Rolling 1 or 20
Sometimes fate blesses or curses a combatant, causing the novice to hit and the veteran to miss.

If the d20 roll for an attack is a 20, the attack hits regardless of any modifiers or the target's AC. In addition, the attack is a Critical Hit, as explained later on this page.

If the d20 roll for an attack is a 1, the attack misses regardless of any modifiers or the target's AC.

Unseen Attackers and Targets
Combatants often try to escape their foes' notice by hiding, casting the Invisibility spell, or lurking in darkness.

When you attack a target you can't see, you have disadvantage on the attack roll. This is true whether you're guessing the target's location or you're targeting a creature you can hear but not see. If the target isn't in the location you targeted, you automatically miss, but the Dungeon Master typically just says that the attack missed, not whether you have guessed the target's location correctly.

When a creature can't see you, you have advantage on attack rolls against it.

If you are hidden - both unseen and unheard - you give away your location when the attack hits or misses.

Ranged Attacks
When you make a ranged attack, you fire a bow or crossbow, hurl a handaxe, or otherwise send projectiles to strike a foe at a distance. A creature might shoot spines from its tail. Many spells also involve making a ranged attack.

Range
You can make ranged attacks only against targets within a specified range.

If a ranged attack, such as one made with a spell, has a single range, you can't attack a target beyond this range.

Some ranged attacks, such as those made with a longbow or shortbow, have two ranges. The smaller number is the normal range, and the larger number is the long range. Your attack roll has disadvantage when your target is beyond normal range, and you can't attack a target beyond the long range.

Ranged Attacks in Close Combat
Aiming a ranged weapon is more difficult when a foe is right next to you. When you make a ranged attack with a weapon, a spell, or some other means, you have disadvantage on the attack roll if you are within 5 feet of a hostile creature who can see you and who isn't incapacitated.

Melee Attacks
Used in hand-to-hand combat, a melee attack allows you to attack a foe within your reach. A melee attack typically uses a handheld weapon such as a sword, a warhammer, or an axe. A typical creature makes a melee attack when it strikes with its claws, horns, teeth, tentacles, or other body part. A few spells also involve making a melee attack.

Most creatures have a 5-foot reach and can thus attack targets within 5 feet of them when making a melee attack. Certain creatures (typically those larger than medium) have melee attacks with greater reach than 5 feet, as noted in their stat block.

When you are unarmed, you can fight in melee by making an Unarmed Strike, as shown in the Weapon Table, in the Weapons section of the Equipment page.

Opportunity Attacks
In a fight, everyone is constantly watching for enemies to drop their guard. You can rarely move heedlessly past your foes without putting yourself in danger; doing so provokes an opportunity attack.

You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature. The attack interrupts the provoking creature's movement, occurring right before the creature leaves your reach.

You can avoid provoking an opportunity attack by taking the Disengage action. You also don't provoke an opportunity attack when you teleport or when someone or something moves you without using your movement, action, or reaction. For example, you don't provoke a opportunity attack if an explosion hurls you out of a foe's reach or if gravity causes you to fall past an enemy.*

Two-Weapon Fighting
When you take the Attack action and attack with a Light melee weapon you're holding in one hand, you can use a bonus action to attack with a different Light melee weapon that you're holding in the other hand. You don't add your ability modifier to the damage of the bonus attack, unless that modifier is negative.

If either weapon has the Thrown property, you can throw the weapon, instead of making a melee attack with it,

Grappling
When you want to grab a creature or wrestle with it, you can use the Attack action to make a special melee attack, a grapple. If you're able to make multiple attacks with the Attack action, this attack replaces one of them.

The target of your grapple must be no more than one size larger than you, and it must be within your reach. Using at least one free hand, you try to seize the target by making a grapple check, a Strength (Athletics) check contested by the target's Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use). If you succeed, you subject the target to the grappled condition (see the Conditions page). The condition specifies the things that end it, and you can release a target whenever you like (no action required).

'''Escaping a Grapple. '''A grappled creature can use its action to escape. To do so, it must succeed on a Strength (Athletics) or Dexterity (Acrobatics) check contested by your Strength (Athletics) check.

'''Moving a Grappled Creature. ''' When you move, you can drag or carry the grappled creature with you, but your speed is halved, unless the creature is two or more sizes smaller than you.

Shoving a Creature
Using the Attack action, you can make a special melee attack to shove a creature, either to knock it prone or push it away from you. If you're able to make multiple attacks with the attack action, this attack replaces one of them.

The target of your shove must be no more than one size larger than you, and it must be within your reach. You make a Strength (Athletics) check contested by the target's Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use). If you win the contest, you either knock the target prone or push it 5 feet away from you.

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.

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.

Damage and Healing
Injury and the risk of death are constant companions of those who explore the dangerous places of the world. The thrust of a sword, a well-placed arrow, or a blast of flame from a Fireball spell all have the potential to damage, or even kill, the hardiest of creatures.

Hit Points
Hit points represent a combination of physical and mental durability, the will to live, and luck. Those with fewer hit points are more fragile.

A creature's current hit points (usually just called hit points) can be any number from the creature's hit point maximum down to 0. This number changes frequently as a creature takes damage or receives healing.

Whenever a creature takes damage, that damage is subtracted from its hit points. The loss of hit points has no effect on a creature's capabilities until the creature drops to 0 hit points.

Damage Rolls
Each weapon, spell, and harmful creature ability specifies the damage it deals. You roll the damage die or dice, add any modifiers, and apply the damage to your target. Magic weapons, special abilities, and other factors can grant a bonus to damage.

When attacking with a weapon, you add your ability modifier - the same modifier you used for the attack roll - to the damage. A spell tells you which dice to roll for damage and whether to add any modifiers.

If a spell or other effect deals damage to more than one target at the same time, roll the damage once for all of them. For example, when a Wizard casts Fireball or a Cleric casts Flame Strike, the spell's damage is rolled once for all creatures caught in the blast.

Critical Hits
When you score a critical hit, you get to roll extra dice for the attack's damage against the target. Roll all of the attack's damage dice twice and add them together. Then add any relevant modifiers as normal. To speed up play, you can roll all the damage dice at once.

For example, if you score a critical hit with a dagger, roll 2d4 for the damage, rather than 1d4, and then add your relevant ability modifier. If the attack involves other damage dice, such as from the Rogue's Sneak Attack feature, you roll those dice twice as well.

Damage Types
Different attacks, damaging spells, and other harmful effects deal different types of damage. Damage types have no rules of their own, but other rules, such as damage resistance, rely on the types.

The damage types follow, with examples to help a new Dungeon Master assign a damage type to a new effect.
 * Acid. The corrosive spray of a Black Dragon's breath, and the dissolving enzymes secreted by a Blue Slime deal acid damage.
 * Bludgeoning. Blunt force attacks - hammers, falling, constriction, and the like - deal bludgeoning damage.
 * Cold. The infernal chill radiating from a Glacies's spear and the frigid blast of a White Dragon's breath deal cold damage.
 * Fire. Red Dragons breathe fire, and many spells conjure flames to deal fire damage.
 * Force. Force is pure magical energy focused into a damaging form.  Most effects that deal force damage are spells, including Magic Missile and Spiritual Weapon.
 * Lightning. A Lightning Bolt spell and a Blue Dragon's breath deal lightning damage.
 * Necrotic. Necrotic damage, dealt by certain undead and a spell such as Chill Touch, withers matter and saps energy.
 * Piercing. Puncturing and impaling attacks, including spears and creatures' bites, deal piercing damage.
 * Poison. Venomous stings and the toxic gas of a Green Dragon's breath deal poison damage.
 * Psychic. Mental abilities such as a Mind Flayer's psionic blast deal psychic damage.
 * Radiant. Radiant damage, dealt by a Cleric's Flame Strike spell, or a Valkyrie's smiting weapon, sears the flesh like fire and overloads the spirit with power.
 * Slashing. Swords, axes, and creatures' claws deal slashing damage.
 * Thunder. A concussive burst of sound, such as the effect of the Thunderwave spell, deals thunder damage.

Damage Resistance and Vulnerability
Some creatures and objects are exceedingly difficult or unusually easy to hurt with certain types of damage.

If a creature or an object has resistance to a damage type, damage of that type is halved against it. If a creature or an object has vulnerability  to a damage type, damage of that type is doubled against it.

Resistance and then vulnerability are applied after all other modifiers to damage. For example, a creature has resistance to bludgeoning damage and is hit by an attack that deals 25 bludgeoning damage. The creature is also within a magical aura that reduces all damage by 5. The 25 damage is first reduced by 5 and then halved, so the creature takes 10 damage.

Multiple instances of resistance or vulnerability that affect the same damage type count as only one instance. For example, if a creature has resistance to fire damage as well as resistance to all nonmagical damage, the damage of a nonmagical fire is reduced by half against the creature, not reduced by three-quarters.

Healing
Unless it results in death, damage isn't permanent. Even death is reversible through powerful magic. Rest can restore a creature's hit points (as explained on the Adventuring page), and magical methods such as a Cure Wounds spell or a Potion of Healing can remove damage in an instant.

When a creature receives healing of any kind, hit points regained are added to its current hit points. A creature's hit points can't exceed its hit point maximum, so any hit points regained in excess of this number are lost. For example, a Druid grants a Ranger 8 points of healing. If the Ranger has 14 current hit points and has a hit point maximum of 20, the ranger regains 6 hit points from the druid, not 8.

A creature that has died can't regain hit points until magic such as the Revivify spell has restored it to life.

Dropping to 0 Hit Points
When you drop to 0 hit points, you either die outright or fall unconscious, as explained in the following sections.

Instant Death
Massive damage can kill you instantly. When damage reduces you to 0 hit points and there is damage remaining, you die if the remaining damage equals or exceeds your hit point maximum. For example, a cleric with a maximum of 12 hit points currently has 6 hit points. If he takes 18 damage from an attack, he is reduced to 0 hit points, but 12 damage remains. Because the remaining damage equals his hit point maximum, the cleric dies.

Falling Unconscious
If damage reduces you to 0 hit points and fails to kill you, you fall unconscious (see the Conditions page). This unconsciousness ends if you regain any hit points.

Death Saving Throws
Whenever you start your turn with 0 hit points, you must make a special saving throw, called a death saving throw, to determine whether you creep closer to death or hang onto life. Unlike other saving throws, this one isn't tied to any ability score. You are in the hands of fate now, aided only by spells and features that improve your chances of succeeding on a saving throw.

Roll a d20. If the roll is 10 or higher, you succeed. Otherwise, you fail. A success or failure has no effect by itself. On your third success, you become stable (see below). On your third failure, you die. The successes and failures don't need to be consecutive; keep track of both until you collect three of a kind. The number of both is reset to 0 if you regain ant hit points or become stable.

'''Rolling 1 or 20. '''When you make a death saving throw and roll a 1 on the d20, it counts as two failures. If you roll a 20 on the d20, you regain 1 hit point.

'''Damage at 0 Hit Points. '''If you take any damage while you have 0 hit points, you suffer a death saving throw failure. If the damage is from a critical hit, you suffer two failures instead. If the damage equals or exceeds your hit point maximum, you suffer instant death.

Stabilizing a Creature
The best way to save a creature with 0 hit points is to heal it. If healing is unavailable, the creature can at least be stabilized so it isn't killed by a failed death saving throw.

You can use your action to administer first aid to an unconscious creature and attempt to stabilize it, which requires a successful DC 10 Wisdom (Medicine) check.

A stable creature doesn't make death saving throws, even though it has 0 hit points, but it does remain unconscious. The creature stops being stable, and must start making death saving throws again, if it takes any damage. A stable creature that isn't healed regains 1 hit point after 1d4 hours.

Enemies and Death
Most Dungeon Masters have an enemy die if it drops to 0 hit points, rather than having it fall unconscious and make death saving throws. Some conditions can circumvent this, such as dying in an Undead realm, or being reduced to 0 hit points by a weapon made out of Demon-Realm Silver.

Mighty villains and special nonplayer characters are common exceptions as well; the Dungeon Master might have them fall unconscious and follow the same rules as player characters,

Knocking a Creature Out
Sometimes, an attacker wants to incapacitate a foe, rather than deal a killing blow. When an attacker reduces a creature to 0 hit points with a melee attack, the attacker can knock the creature out. The attacker can make this choice the instant the damage is dealt. The creature falls unconscious and is stable.

Temporary Hit Points
Some spells and special abilities confer temporary hit points to a creature. Temporary hit points aren't actual hit points; they are a buffer against damage, a pool of hit points that protect you from injury.

When you have temporary hit points and take damage, the temporary hit points are lost first, and any leftover damage carries over to your normal hit points. For example, if you have 5 temporary hit points and take 7 damage, you lose the temporary hit points and then take 2 damage.

Because temporary hit points are separate from your actual hit points, they can exceed your hit point maximum. A character can, therefore, be at full hit points and receive temporary hit points.

Healing can't restore temporary hit points, and they can't be added together. If you have temporary hit points and receive more of them, you decide whether to keep the ones you have or to gain the new ones. For example, if a spell grants you 12 temporary hit points when you already have 10, you can have 12 or 10, not 22.

If you have 0 hit points, receiving temporary hit points doesn't restore you to consciousness or stabilize you. They can still absorb damage directed at you while you're in that state, but only true healing can save you.

Unless a feature that grants you temporary hit points has a duration, they last until they're depleted or you finish a long rest.

Mounted Combat
A knight charging into battle on a warhorse, a Wizard casting a spell from the back of a Great Eagle, or a Cleric soaring through the sky on a Celestial Pegasus all enjoy the benefits of speed and mobility that a mount can provide.

A willing creature that is at least one size larger than you and has an appropriate anatomy can serve as a mount, using the following rules.

Mounting and Dismounting
Once during your move, you can mount a creature that is within 5 feet of you or dismount. Doing so costs an amount of movement equal to half your speed. For example, if your speed is 30 feet, you must 15 feet of movement to mount a rideable creature. Therefore, you can't mount it if you don't have 15 feet of movement left or if your speed is 0.

If an effect moves your mount against its will while you're on it, you must succeed on a DC 10 Dexterity saving throw or fall off the mount, landing prone in a space within 5 feet of it. If you're knocked prone while mounted, you must make the same saving throw.

If your mount is knocked prone, you can use your reaction to dismount it as it falls and land on your feet. Otherwise, you are dismounted and fall prone in a space within 5 feet.

Controlling a Mount
While you're mounted, you have two options. You can either control the mount or allow it to act independently. Intelligent creatures, such as Wyverns, act independently.

You can control a mount only if it has been trained to accept a rider. Domesticated horses, donkeys, and similar creatures are assumed to have such training. The initiative of a controlled mount changes to match yours when you mount it. It moves as you direct it, and has only three action options: Dash, Disengage, and Dodge. A controlled mount can move and act even on the turn that you mount it.

An independent mount retains its place in the initiative order. Bearing a ruder puts no restrictions on the actions the mount can take, and it moves and acts as it wishes. It might flee from combat, rush to attack or finish off a badly injured foe, or otherwise act against your wishes.

In either case, if the mount provokes an opportunity attack while you're on it, the attacker can target you or the mount.

Underwater Combat
When adventurers pursue Sahuagin back to their undersea homes, fight off sharks in an ancient shipwreck, or find themselves in a flooded dungeon room, they must fight in a challenging environment. Underwater the following rules apply.

When making a melee weapon attack, a creature that doesn't have a swimming speed (either natural or granted by magic) has disadvantage on the attack roll unless the weapon is a dagger, javelin, shortsword, spear, or trident.

A ranged weapon attack automatically misses a target beyond the weapon's normal range. Even against a target within normal range, the attack roll has disadvantage unless the weapon is a crossbow, a net, or a weapon that is thrown like a javelin (including a spear, trident, or dart).

Creatures and objects that are fully immersed in water have resistance to fire damage.