D&Dtools1

You create a shield of force that can push your attackers away from you.
This spell functions like the shield spell, except that any adjacent creature that makes a melee attack against you is also pushed 5 feet away from you after the attack is resolved.
A successful Reflex save negates this effect, and spell resistance applies.
You can choose the direction of the creature's movement, as long as it ends up farther away from you than it began.
You can't push a creature into a space that it couldn't legally occupy (such as a wall).
If no legal space exists to push the creature, it is unaffected.