This spell causes grasses, weeds, bushes, and even trees to grow thorns and then wrap, twist, and entwine about creatures in the area or those who enter the area, holding them fast. Creatures that stand still are entangled, but experience no other effect and take no damage.
Those that attempt actions (attack, cast a spell with a somatic component, move, and the like) take thorn damage of 1d4 points, and must make a successful dexterity save or remain entangled.
A character who tries to cast a spell must also make a concentration check (DC10 + spell level + damage taken) or lose the spell.
A creature that fails the dexterity save is restrained. An entangled creature can try to break free and move at half normal speed by using a full-round action to make a Strength check. A non-entangled creature can move through the area as difficult terrain, taking damage as described above. Each round non-entangled creatures remain in the area after freeing themselves, the plants attempt to entangle them (To hit and then dex save required to entangle and damage).
The plants provide one-quarter cover for every 5 feet of substance between a creature in the area and an opponent—one-half for 10 feet of briar web, three-quarters for 15 feet, and total cover for 20 feet or more.
Please Note: The DM may alter the effects of the spell somewhat, based on the nature of the available plants.