Every skill earned causes a new piece of the Tatau to burn itself into existence on Jason's arm.
Every time he earns enough experience to earn a Skill Point, he can invest it in one of three different skill trees: the Heron, the Shark, and the Spider. In gameplay terms, the Tatau actually reflects Jason's level. The third base is applied by Citra herself, while Jason is unconscious, after undergoing the final challenge and defeating the mental Giant. The second of these bases is also applied by Dennis, after Citra agrees to let Jason prove his worthiness to be a Warrior. There are three of these bases, with the first being the one Dennis applies in Amanaki Village. However, it cannot spread past a certain point unless a new 'base' is drawn by a Rakyat tattooist. The Tatau spreads across his arm by itself, with new elements burning into place with a glow of light. The Tatau itself seems to be magical as Jason grows stronger and wiser, the Tatau also enhances all of his physical abilities, most notably his strength, speed, stamina, intelligence, instincts & accelerates his healing speeds. Dennis tells Jason that he is a warrior and his Tatau determines who he is. After escaping Vaas' camp, Jason Brody wakes up to find Dennis giving him a tattoo on his left arm. The Tatau is an important element in Far Cry 3.
