House Rule: Inscribe Magic

Vaguely inspired by Talysman's recent thoughts on the Read Magic spell.

The reverse of Read Magic, known as Inscribe Magic allows the caster to inscribe a mark, pictogram, or message of up to six words or symbols in length plus the character level of the caster making the mark. If the caster wishes, she may make the mark unintelligible or even invisible except to readers whom she specifically designates. An invisible mark can be seen, but not understood, by use of a Detect Magic or See Invisible spell. Only a Read Magic or True Seeing spell will make the writing legible to someone who the caster does not wish to read the mark. Inscribe Magic may also be used to mark a living or undead creature, in which case it will fade after a number of weeks equal to the caster's level.