A forest, also referred to as a wood or woods, is a large group of trees. A forest can be visually divided into the overstory, with the trees' crowns, and the understory, where also herbs and mosses are. Depending on the type of trees and plants that grow in a forest, its density can vary greatly. Within a forest, there can be open spaces, houses or even villages.

In realistic role-play, especially in a modern or future era, a forest is usually inhabited only by animals. In historical role-plays, hermits and similar figures may inhabit the woods, and creatures such as witches, dryads and wood elves back this group up in the case of a fantasy role-play.