A tattoo is a (mostly) permanent form of body modification consisting of patterns created by injecting ink into the wearer's skin. Tattooing seems to have existed since the stone age (or at least, has been found in stone-age cultures within historical record) and continues into the modern day.
Depending on the culture, tattooing will serve a variety of purposes. In those in which it originates, tattoos tend to be administered as a right of passage - sometimes to the extent that an individual's entire life history can be read from his inks1. In those cultures that have adsorbed tattooing from elsewhere it tends to be more decorative than significant, but can still have meaning in some circumstances.
Also, tattooing is not always voluntary - animals, or even people, have been known to be tattooed either as a symbol of ownership or by way of punishment. Or even for decoration to please their owner.
Short of flaying off the marked skin, the only practical way to remove a tattoo seems to be to break down the ink with a laser - a slow, painful process which is not 100% effective, although some colours of ink fade naturally over time in sunlight. Many wearers prefer to have their previous tattoos covered up or modified with further work.
Game and Story Use
- Tattooing is permanent - tattoos that indicate your membership of a specific group may come back to haunt you, whether you happen to be a ex-Royal Navy sailor trying to avoid the press or a former gangster trying to go straight.
- Those contemplating a decorative tattoo should make damned sure that it doesn't mean anything before they have it fitted - those cool inks you decided to copy from that guy in the nightclub may have inadvertently marked you as a Thief in Law or member of some other organisation that doesn't appreciate imitators.
- Japan is a key example of a culture in which getting tattoos are frowned upon - although the taboo is not as strong as it was, there was a time that they were considered so transgressive that only a yakuza would consent to wear one.
- Note that thing about flaying off the skin - many organisations that use tattoos as marks of membership have at least some history of cutting or burning them off from ex-members or others not considered entitled to wear them.
- Magical tattoos are always popular.
- Creepier villains may have a collection of tanned skins displaying the former owner's tattoos.
- The Yakuza have a reputation for doing this to memorialise their own casualties.
- For cultures with meaningful tattoos, PCs with the right skill set may be able to learn quite a lot about someone from their inks. Of course, there may be varying degrees of how much given tattoos are displayed (for example, clan membership and status may be tattooed on the wearer's face, whereas family details might be recorded on the torso and normally covered by clothes).