An overrun is a standard action that allows you to move up to your speed in order to move through an opponent’s square. You can only overrun targets that are no more than 1 size category larger than you.

Your target may choose to prevent your move or get out of the way.

Flanking and cover bonuses apply.

When you move towards your target, you get a +1 for every 10 feet you move toward the target as part of your standard action.

Otherwise, an overrun is an opposed base attack bonus check with Str and Dex modifiers added, as well as class, race, and feat abilities. The larger creature gets a +2 for every size category it is larger than his opponent.

Overrun Failure
If the target prevents your movement and your check fails, then your action ends adjacent to the target.

Great Success
If your check beats the opponent by 5 or more, then you knock the target prone


The Storm of Insurrection Jrrtolkien