Knot

Regular 
Ties a knot that cannot be untied without magic (though the rope can be cut, of course). The knot unties when someone says the password (specified at casting) while touching the rope at any point along its length. 
Thus, a rope tied at the top of a cliff will come loose when someone at the bottom of the cliff says the password, if he can touch the rope. Knot also works for string, chastity belts, etc. 
The Undo spell also unties a Knot spell, but the Knot spell gets a resistance roll.

Duration: Until the password is spoken, or the rope is cut or broken! 
Cost: 2. Cannot be maintained – must be recast if the rope is untied. 
Time to cast: 3 seconds. 
Prerequisite: Stiffen.

Item 
Rope. Any knot tied with this rope cannot be untied without magic. A password is set when the rope is enchanted. The enchantment is broken if the rope is cut.  
Energy cost to cast: 20 per foot of rope.