Binding Circle
From AmtWiki
One of the Summoning Circles; a type of Terrain from the Celestial Codex.
Materials
Represented by at least seven 3-foot strips of yellow cloth laid end-to-end to form a circle.
Effects
Any free-willed (not conjured) Celestial or Infernal Monster who enters the Binding Circle may not leave the area until the Circle is broken (see Limitations below) or it is slain or Banished. Conjured Celestial or Infernals who enter this area are instantly Banished.
Limitations
If at any time the circle is physically broken (such as by a player accidentally slipping on one of the strips), the monster is instantly freed and able to move as normal. Note, Bound Monsters may not touch the circle or disrupt it in any way.