Squeezing
In some cases, you may have to squeeze into or through an area that isn’t as wide as the space you take up. You can squeeze through or into a space that is at least half as wide as your normal space. Each move into or through a narrow space counts as if it were 2 squares, and while squeezed in a narrow space you take a -4 penalty on attack rolls and a -4 penalty to AC.
When a Large creature (which normally takes up four squares) squeezes into a space that’s one square wide, the creature’s miniature figure occupies two squares, centered on the line between the two squares. For a bigger creature, center the creature likewise in the area it squeezes into.
A creature can squeeze past an opponent while moving but it can’t end its movement in an occupied square.
To squeeze through or into a space less than half your space’s width, you must use the Escape Artist skill. You can’t attack while using Escape Artist to squeeze through or into a narrow space, you take a -4 penalty to AC, and you lose any Dexterity bonus to AC.