Web of Shadows

The caster fills a 15' radius area with semi-solid shadows that reach up from the ground and out from any walls to hold all creatures in the area.  The creatures must make a strength check against the SR of the caster or be reduced to zero movement.  If the save is failed,  all attack rolls or actions requiring rolls by the target are made at disadvantage, as well.

Casting the spell at a higher spell level will extend the duration by 1 minute for each additional level used this way.