Stumble Gap

Conjuration (Creation)
Level: Artificer * 1, Sorcerer */Wizard * 1
Components: V, S, F (miniature shovel costing 10 gp)
Casting Time: 1 Standard Action
Range: close (25 ft. + 5 ft./2 levels)
Effect: see text
Duration: 1 round + 1 round/level
Saving Throw: Reflex partial
Spell Resistance: no
  You create a shallow extradimensional hole perfectly sized to Trip anyone who steps within it. This hole occupies a single 5-foot square with a depth of six inches. Any creature occupying the square when you first create the hole, or who later steps into the square containing the hole, must make a Reflex saving throw to avoid Falling Prone in an adjacent square and taking 1d6 points of damage. A creature that makes its saving throw still stumbles ever so slightly and takes a -1 penalty on all rolls and checks for 1 round. The spell has no effect on creatures adjacent to the square containing the hole.