Runetrue
(Abjuration, Invocation)

Range:  Special
Components:  V, M
Duration:  1 turn per level
Casting Time:  5 rounds
Area of Effect:  Special
Saving Throw:  None

This is a spell that allows wizards to infuse the magical symbols they draw (see below) with the power needed to repel summoned or extraplanar creatures. The maximum Hit Die creature that may be fenced in or out is equal to the wizard's level plus four.
Note: as the above implies, it is possible to fence out summoned or extraplanar creatures of less than 4 HD by using the symbols without runetrue.
The only symbols that this spell empowers are listed below:

Symbol	Protects from
Pentacle	Demons, demodands
Pentagram	Devils, daemons
Magic circle	Spirits of good
Magic (protection) circle	Undead
Thaumaturgic circle	Spirits of nature and neutrality
Thaumaturgic triangle	Elementals

The wizard must still create the symbol manually, using anything from a stick to gold inlay.

