Skip to content

Instantly share code, notes, and snippets.

@jerclarke

jerclarke/Jer-dnd-combat-notes.md

Last active February 3, 2020 14:52
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save jerclarke/ebf314fe7bf6e46c7164cd98968629b3 to your computer and use it in GitHub Desktop.
Save jerclarke/ebf314fe7bf6e46c7164cd98968629b3 to your computer and use it in GitHub Desktop.
Download ZIP
Jer's reference notes on D&D 5e combat
Raw
Jer-dnd-combat-notes.md

Jer's reference notes on D&D 5e combat

Surprise

  • The DM determines who might be surprised for the first round of combat
  • If neither side tries to be stealthy, they automatically notice each other.
  • Notice check: DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side.
  • Any character or monster that doesn't notice a threat is surprised at the start of the 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

  • Everyone does a dex check to determine initiative order
  • Tied monsters: DM decides
  • Tied players: players decide
  • Tied monster+player: DM decides or d20 contest to see who goes first

Turns and Actions

  • 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 first.
  • Free actions
    • You can communicate however you are able, through brief utterances and gestures, as you take your turn.
    • You can draw your weapon for free
    • You can also interact with one object or feature of the environment for free, during either your move or your action. If you want to interact with a second object, you need to use your action.
    • More Free actions
    • The DM might require you to use an action for any of these activities when it needs special care or when it presents an unusual obstacle. This constitutes the Use an Object action.
  • Some magic items and other special objects always require an action to use, as stated in their descriptions.

Bonus Actions

  • Various class features, spells, and other abilities let you take an additional action on your turn called 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 can take only one bonus action on your turn, so you must choose which bonus action to use when you have more than one available.
  • You choose when to take a bonus action during your turn, unless the bonus action's timing is specified
  • Anything that deprives you of your ability to take actions also prevents you from taking a bonus action.

Reactions

  • Certain special abilities, spells, and situations allow you to take a special action called a reaction, an instant response to a trigger of some kind, which can occur on your turn or on someone else's.
  • Opportunity attacks are 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.

Full actions

  • Attack: Make one melee or ranged attack. Features can allow more than one attack with the attack action
  • Spells: Cast a spell with a casting time of one action
  • Dash: Double your movement for the current turn. Any increase or decrease to your speed changes this additional movement by the same amount.
  • Disengage: If you take the Disengage action, your movement doesn't provoke opportunity attacks for the rest of the turn.
  • Dodge: 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: Lend your aid to another creature in the completion of a task.
    • Help w/ Ability check creature you aid gains advantage on the next ability check it makes to perform the task you are helping with (before the start of your next turn)
    • Help w/ Attack: Aid a friendly creature in attacking a creature within 5 feet of you, they gain advantage on first attack role (before the start of your next turn)
  • Hide: Make a Dexterity (Stealth) check in an attempt to hide. See "Unseen Attackers and Targets"
  • Search: Devote your attention to finding something. Depending on the nature of your search, the DM might have you make a Wisdom (Perception) check or an Intelligence (Investigation) check.
  • Use an Object: Most object interactions are Free actions (see above) that you do while moving and doing your normal action. If an object requires your action for its use, you take the Use an Object action. This action is also useful when you want to interact with more than one object on your turn.

Ready action

  • Lets you act using your reaction before the start of your next turn.
  • Indicate a perceivable circumstance that will trigger your reaction.
  • Indicate the action or movement (up to your movement speed) you will take in response to that trigger
  • When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger.
  • Readying spells:
    • 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.
    • If your concentration is broken, the spell dissipates without taking effect.

Movement

  • On your turn, you can move a distance up to your speed.
  • 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.
  • You deduct the distance of each part of your move from your speed until it is used up or until you are done moving.
  • You can break up your movement on your turn, using some of your speed before and after your action, including a mix of attacking, moving, and more attacking.
  • If you have more than one speed, such as your walking speed and a 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 current move.
  • 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.
  • Moving through creature's space
    • Non-hostile: can move through a nonhostile creature's space (it is difficult terrain as described above)
    • Hostile: 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.
    • 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.
  • Flying: 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.

Creature size and taking up space

Size Space
Tiny 2 1/2 by 2 1/2 ft.
Small 5 by 5 ft.
Medium 5 by 5 ft.
Large 10 by 10 ft.
Huge 15 by 15 ft.
Gargantuan 20 by 20 ft. or larger
  • A creature's space is the area in feet that it effectively controls in combat.
  • A creature's space also reflects the area it needs to fight effectively.
  • Limits on surrounding creatures
    • Medium combatants: eight creatures can fit in a 5-foot radius around another one.
    • If four Large creatures crowd around a Medium or smaller one, there's little room for anyone else.
    • As many as twenty Medium creatures can surround a Gargantuan one.
  • Squeezing into small spaces (difficult terrain + disadvantage)
    • A creature can squeeze through a space that is large enough for a creature one size smaller than it. i.e. 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
    • Squeezing creatures have disadvantage on attack rolls and Dexterity saving throws.
    • Attack rolls against squeezing creatures have advantage while they are in the smaller space.

Prone

  • You can drop prone without using any of your speed.
  • Standing up costs an amount of movement equal to half your speed.
  • A prone creature's only movement option is to crawl
  • Every foot of movement while crawling costs 1 extra foot. Crawling 1 foot in difficult terrain, therefore, costs 3 feet of movement.
  • The creature has disadvantage on attack rolls.
  • Attack on prone creature within 5 feet: Advantage
  • Ranged (5'+) on prone creature: Disadvantage

Attacks

  • Choose a target within range, determine modifiers (adv/dis)
  • If the total of the roll plus modifiers equals or exceeds the target's Armor Class (AC), the attack hits.
  • 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 monster makes an attack roll, it uses whatever modifier is provided in its stat block.
  • 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.
  • Melee The ability modifier used for a melee weapon attack is Strength
  • Ranged: The ability modifier used for a ranged weapon attack is Dexterity.
  • Finesse/thrown that have the finesse or thrown property break this rule.
  • Spells: spells also require an attack roll. The ability modifier used for a spell attack depends on the spellcasting ability of the spellcaster, as explained in chapter 10.
  • Rolling a 1 means you always miss, rolling a 20 means you always hit
  • Critical Hits
    • When you score a critical hit (natural 20), 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.
  • 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.
  • Unarmed strike: On a hit, an unarmed strike deals bludgeoning damage equal to 1 + your Strength modifier. You are proficient with your unarmed strikes.

Opportunity Attacks

  • 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 occurs 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.

Unseen Attackers and Targets

  • Disadvantage on attack roll when attacking unseen creatures
  • Targets you can't see: Hidden, invisible
  • Applies 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 DM typically just says that the attack missed, not whether you guessed the target's location correctly.
  • Advantage on attack roll when attacking creatures that can't see you
  • If you are hidden — both unseen and unheard — when you make an attack, you give away your location when the attack hits or misses.

Ranged Attacks

  • 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 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 (dis)
    • If you make a ranged attack within 5 feet of a hostile creature who can see you and isn't incapacitated, you have disadvantage.
    • Applies to weapons, spells, and other ranged attacks.

Two-Weapon Fighting

  • When you take the Attack action and attack with a light melee weapon that 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

  • Use the Attack action to make a special melee attack, grabbing a creature or wrestle with it
    • 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 must be within your reach.
    • You must have one free hand.
  • You try to seize the target by making a grapple check instead of an attack roll:
    • a Strength (Athletics) check contested by the target's Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use).
    • You succeed automatically if the target is incapacitated.
  • Target gets grappled condition if you succeed:
    • 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
    • The condition also ends if an effect removes the grappled creature from the reach of the grappler or grappling effect
  • 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

  • Use the Attack action to 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 must be no more than one size larger than you and must be within your reach.
  • Instead of making an attack roll, you make a Strength (Athletics) check contested by the target's Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use).
  • You succeed automatically if the target is incapacitated.
  • If you succeed, you either knock the target prone or push it 5 feet away from you.

Cover

  • Target is more difficult to harm if it has cover
  • A target can benefit from cover only when an attack or other effect originates on the opposite side of the cover.
  • If a target is behind multiple sources of cover, only the most protective degree of cover applies; the degrees aren't added together.
  • Half 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.
  • Three-Quarters Cover: 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.
  • **Total Cover: **
    • 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 Resistance and Vulnerability

  • 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.
  • Multiple instances of resistance or vulnerability that affect the same damage type count as only one instance.

Healing and death

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

Death Saving Throws

  • When you drop to 0 hit points, you either die outright or fall unconscious.
  • Instant Death: 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.
  • Falling Unconscious: If damage reduces you to 0 hit points and fails to kill you, you fall unconscious. 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
    • Roll a d20, with no ability modifier
    • If the roll is 10 or higher, you succeed. Otherwise, you fail.
    • On your third success, you become stable
    • On your third failure, you die.
    • The number of both is reset to zero when you regain any hit points or become stable.
    • Rolling 1: When you make a death saving throw and roll a 1 on the d20, it counts as two failures.
    • Rolling 20: If you roll a 20, 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

  • You can stabilize a creature with 0 hit points to avoid it being killed by death saving throws.
  • 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.
  • If the creature takes any damage it stops being stable and restarts death saving throws.
  • A stable creature that isn't healed regains 1 hit point after 1d4 hours.

Knocking a Creature Out

  • An attacker can 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

  • 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.
  • Because temporary hit points are separate from your actual hit points, they can exceed your hit point maximum.
  • Healing can't restore temporary hit points
  • Temporary hit points 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.
  • 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.

Spellcasting

Concentration

Resting and Hit Dice

Short Rest

  • A period of downtime, at least 1 hour long, during which a character does nothing more strenuous than eating, drinking, reading, and tending to wounds.
  • Characters can spend Hit Dice during short rests as described below.

Long Rest

  • A long rest is a period of extended downtime, at least 8 hours long, during which a character sleeps for at least 6 hours and performs no more than 2 hours of light activity, such as reading, talking, eating, or standing watch.
  • At the end of a long rest, a character regains all lost hit points.
  • A character can't benefit from more than one long rest in a 24-hour period, and a character must have at least 1 hit point at the start of the rest to gain its benefits.
  • Interruption (1 hour): the rest is interrupted by a period of strenuous activity - at least 1 hour of walking, fighting, casting spells, or similar adventuring activity - the characters must begin the rest again to gain any benefit from it.

Hit Dice

  • A character has a maximum number of Hit Dice equal to their level.
  • Hit Dice are spent to regain HP during Short Rests, and up to half of which are regained during Long Rests, as described below.
  • Short Rest: Spending Hit Dice
    • At the end of a Short Rest characters can spend one or more of their current Hit Dice.
    • For each die used, the player rolls the die and heals HP equal to the result plus their Constitution modifier. Minimum of 0.
    • The player can decide to spend an additional Hit Die after each roll.
  • Long Rest: Regaining Hit Dice
    • At the end of a long rest, a character regains spent Hit Dice, up to half of the character's total number of hit dice. Minimum of one die.
    • For example, if a character has eight Hit Dice, they can regain four spent Hit Dice upon finishing a long rest.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment