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.
|2½ by 2½ ft.
|5 by 5 ft.
|Giant rat, goblin
|5 by 5 ft.
|10 by 10 ft.
|15 by 15 ft.
|Fire Giant, treant
|20 by 20 ft. or larger
|Kraken, purple worm
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 twenty 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’s in the smaller space.
Monster Hit Dice by Size
|Hit Dice by Size
|Average HP per Die
A monster’s Constitution modifier also affects the number of hit points it has. Its Constitution modifier is multiplied by the number of Hit Dice it possesses, and the result is added to its hit points. For example, if a monster has a Constitution of 12 (+1 modifier) and 2d8 Hit Dice, it has 2d8 + 2 hit points (average 11).
- Wizards RPG Team. SRD-OGL v5.1 (5e) (2015.05.06). Wizards of the Coast. p. 84-85, 91-92.
- Editor's Note: This articles was taken from two places in the SRD; the Movement section (p.84-85) and the Combat section (p.91-92).
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