The Pit of Shades can be cast on any one unengaged enemy unit anywhere on the table. If successfully cast, the ground falls away beneath the unit's feet toppling them to their doom.
Take the 3" template and place it over a single target enemy unit. All models in the target unit completely under the template are automatically hit and those touched by it are hit on a 4+ on a D6. Models hit suffer 1 Strength 3 hit. In addition, the player whose unit is affected rolls a D6: on a score of 1-3 the unit climbs out of the pit (this counts as moving for the purposes of shooting, etc) and moves at half speed next turn, on a score of 4-6 the unit is unaffected. The pit closes up after the unit has clambered out of it.