Sorcery/Powers: Tattoo Magic

Sorcery/Powers: Tattoo Magic

There's at least two kinds of special tattoos in D&D 3.5 - Thayan magic tattoos and psionic tattoos. If you look closely at the feats that allow their creation, you will see that they are almost exactly the same. How to make such things in GURPS? I'll tell you what I think about it.

Essentially, the tattoos are either permanent or single use enchanted items, so let's treat them as such. You can only create tattoos out of spells that target a creature. This calls for the creation of two new enchanted item forms for Sorcery. Psionic tattoos work identically, but use Psionic Enchantment.

    Permanent Tattoo (x0.95)

   This is a "Usually On" item (GURPS Thaumatology: Sorcery, p. 27). Activating and deactivating it requires the user to touch it and perform a Ready maneuver. The tattoo can be removed via mundane tattoo erasure procedures and supernatural effects that remove tattoos or writings.

    Single-Use Tattoo (x0.19)

   This is a single use item made from a Buff or Resisted spell. Activating it requires the user to touch it and perform a Ready maneuver. The tattoo then activates, affecting the user, and dissipates. The tattoo can be removed via mundane tattoo erasure procedures and supernatural effects that remove tattoos or writings.

Alternatively, for single-use tattoos I'd prefer to use Metatronic Scrolls, but replace Scroll, -30% with Tattoo, -5% that represents being vulnerable to erasure.

It also is reasonable to limit the number of tattoos one creature may have. My first thought would be looking at the Armor Locations table (GURPS Low-Tech, p. 100) and treat 100% as 50 character points of tattoos for an SM+0 creature. For bigger or smaller creatures, scale these 50 points by the weight multiplier from p. 21 of GURPS Low-Tech Companion 2, rounding down.