System Reference Document 5.2.1
179
 At the GM’s option, climbing a slippery surface or 
one with few handholds might require a successful 
DC 15 Strength (Athletics) check.
Climb Speed
A Climb Speed can be used in place of Speed to tra-
verse a vertical surface without expending the extra 
movement normally associated with climbing. See 
also “Climbing” and “Speed.”
Concentration
Some spells and other effects require Concentration 
to remain active, as specified in their descriptions. 
If the effect’s creator loses Concentration, the effect 
ends. If the effect has a maximum duration, the ef -
fect’s description specifies how long the creator can 
concentrate on it: up to 1 minute, 1 hour, or some 
other duration. The creator can end Concentration 
at any time (no action required). The following fac -
tors break Concentration.
 Another Concentration Effect. You lose Concen-
tration on an effect the moment you start casting 
a spell that requires Concentration or activate an -
other effect that requires Concentration.
 Damage.  If you take damage, you must succeed 
on a Constitution saving throw to maintain Concen -
tration. The DC equals 10 or half the damage taken 
(round down), whichever number is higher, up to a 
maximum DC of 30.
 Incapacitated or Dead.  Your Concentration ends 
if you have the Incapacitated condition or you die.
Condition
A condition is a temporary game state. The defini -
tion of a condition says how it affects its recipient, 
and various rules define how to end a condition. 
This glossary defines these conditions:
Blinded
Charmed
Deafened
Exhaustion
Frightened
Grappled
Incapacitated
Invisible
Paralyzed
Petrified
Poisoned
Prone
Restrained
Stunned
Unconscious
A condition doesn’t stack with itself; a recipient 
either has a condition or doesn’t. The Exhaustion 
condition is an exception to that rule. 
Cone [Area of Effect]
A Cone is an area of effect that extends in straight 
lines from a point of origin in a direction its creator 
chooses. A Cone’s width at any point along its length 
is equal to that point’s distance from the point of 
origin. For example, a Cone is 15 feet wide at a point 
along its length that is 15 feet from the point of 
origin. The effect that creates a Cone specifies its 
maximum length.
 A Cone’s point of origin isn’t included in the area 
of effect unless its creator decides otherwise.
Cover
Cover provides a degree of protection to a target 
behind it. There are three degrees of cover, each of 
which provides a different benefit to a target: Half 
Cover (+2 bonus to AC and Dexterity saving throws), 
Three-Quarters Cover (+5 bonus to AC and Dexter -
ity saving throws), and Total Cover (can’t be tar -
geted directly). If behind more than one degree of 
cover, a target benefits only from the most protec -
tive degree. See also  “Playing the Game” (“Combat”).
Crawling
While you’re crawling, each foot of movement costs 
1 extra foot (2 extra feet in Difficult Terrain). See 
also “Speed.”
Creature
Any being in the game, including a player’s charac -
ter, is a creature. See also  “Creature Type.”
Creature Type
Every creature, including every player character, 
has a tag in the rules that identifies the type of crea-
ture it is. Most player characters are of the Human -
oid type. These are the game’s creature types:
Aberration
Beast
Celestial
Construct
Dragon
Elemental
Fey
Fiend
Giant
Humanoid
Monstrosity
Ooze
Plant
Undead
The types don’t have rules themselves, but some 
rules in the game affect creatures of certain types 
in different ways.
Critical Hit
If you roll a 20 on the d20 for an attack roll, you 
score a Critical Hit, and the attack hits regardless of 
any modifiers or the target’s AC. A Critical Hit lets 
you 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 mod -
ifiers. See also “Playing the Game” (“Damage and 
Healing”).
Cube [Area of Effect]
A Cube is an area of effect that extends in straight 
lines from a point of origin located anywhere on a 
face of the Cube. The effect that creates a Cube spec -
ifies its size, which is the length of each side.
 A Cube’s point of origin isn’t included in the area 
of effect unless its creator decides otherwise.
Curses
Some game effects curse a creature or an object. 
The effect that confers a curse defines what the 
curse does. Curses can be removed by the Remove 
Curse and Greater Restoration  spells or other magic 
that explicitly ends curses.