Can a symbol of Death or other symbol-based spell using its rules be placed on the caster's armor/robe/outermost covering with touch set as the trigger?
In this case, the caster is attuned to it, and therefore immune to the effects, but if an attacker hits the caster, this triggers the symbol and it may be activated depending on the attacker's current hp or the type of symbol placed and affects all applicable targets within the symbols area of effect.
Is this a viable use of the spell? can the rune be "broken" by a weapon's slash/attack like a circle? etc, etc.