System Reference Document 5.2.1
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playinG on a Grid
If you play using a square grid and miniatures or 
other tokens, follow these rules.
 Squares.  Each square represents 5 feet.
 Speed.  Rather than moving foot by foot, move 
square by square on the grid, using your Speed in 
5-foot segments. You can translate your Speed into 
squares by dividing it by 5. For example, a Speed of 
30 feet translates into 6 squares. If you use a grid of -
ten, consider writing your Speed in squares on your 
character sheet.
 Entering a Square. To enter a square, you must 
have enough movement left to pay for entering. It 
costs 1 square of movement to enter an unoccupied 
square that’s adjacent to your space (orthogonally 
or diagonally adjacent). A square of Difficult Terrain 
costs 2 squares to enter. Other effects might make a 
square cost even more.
 Corners.  Diagonal movement can’t cross the cor -
ner of a wall, a large tree, or another terrain feature 
that fills its space.
 Ranges.  To determine the range on a grid be -
tween two things—whether creatures or objects—
count squares from a square adjacent to one of them 
and stop counting in the space of the other one. 
Count by the shortest route.
Combat
Adventurers encounter many dangerous monsters 
and nefarious villains. In those moments, combat 
often breaks out.
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 
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 begin -
ning of combat when everyone rolls Initiative. Once 
everyone has taken a turn, the fight continues to the 
next round if neither side is defeated.
Combat Step by Step
Combat unfolds in these steps:
1: Establish Positions.  The Game Master deter -
mines where all the characters and monsters are 
located. Given the adventurers’ marching order 
or their stated positions in the room or other lo -
cation, the GM figures out where the adversaries 
are—how far away and in what direction.
2: Roll Initiative.  Everyone involved in the combat 
encounter rolls Initiative, determining the order 
of combatants’ turns.
3: Take Tur ns. Each participant in the battle takes 
a turn in Initiative order. When everyone in -
volved in the combat has had a turn, the round 
ends. Repeat this step until the fighting stops.
Initiative
Initiative determines the order of turns during 
combat. When combat starts, every participant 
rolls Initiative; they make a Dexterity check that 
determines their place in the Initiative order. The 
GM rolls for monsters. For a group of identical crea-
tures, the GM makes a single roll, so each member of 
the group has the same Initiative.
 Surprise. If a combatant is surprised by combat 
starting, that combatant has Disadvantage on their 
Initiative roll. For example, if an ambusher starts 
combat while hidden from a foe who is unaware 
that combat is starting, that foe is surprised.
 Initiative Order. A combatant’s check total is 
called their Initiative count, or Initiative for short. 
The GM ranks the combatants, from highest to 
lowest Initiative. This is the order in which they act 
during each round. The Initiative order remains the 
same from round to round.
 Ties. If a tie occurs, the GM decides the order 
among tied monsters, and the players decide the 
order among tied characters. The GM decides the 
order if the tie is between a monster and a player 
character.
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 first.
 The main actions you can take are listed in “Ac -
tions” earlier in “Playing the Game.” A character’s 
features and a monster’s stat block also provide 
action options. “Movement and Position” later in 
“Playing the Game” gives the rules for movement.
 Communicating. You can communicate however 
you are able—through brief utterances and ges -
tures—as you take your turn. Doing so uses neither 
your action nor your move.
 Extended communication, such as a detailed ex -
planation of something or an attempt to persuade a 
foe, requires an action. The Influence action is the 
main way you try to influence a monster.
 Interacting with Things. You can interact with 
one object or feature of the environment for free, 
during either your move or action. For example, you 
could open a door during your move as you stride 
toward a foe.
 If you want to interact with a second object, you 
need to take the Utilize action. Some magic items 
and other special objects always require an action 
to use, as stated in their descriptions.