Tag!/Fallout: New Vegas

Tag! is a perk in Fallout, Fallout 2, Fallout Tactics, Fallout 3, Fallout: New Vegas, and J.E. Sawyer's Fallout Role-Playing Game.

Fallout, Fallout 2 and Fallout Tactics
Permits a fourth tag skill, adding +20% to it and doubling the rate at which it increases. In Fallout and Fallout 2, this perk also doubles all skill points previously spent on the selected skill (but not the initial 20% bonus).

Fallout 3 and Fallout: New Vegas
The Tag! perk permits a fourth tag Skill, instantly raising it by 15 points.

This perk is the highest skill bonus perk in the game, along with Size Matters, as all others are +10. It is useful for quickly increasing a skill's level.

This perk becomes more useful in Fallout: New Vegas due to the reduced number of skill points received when leveling, the absence Bobbleheads, and fewer skill books. "Tag!" is equivalent to an extra level's worth of skill points with maximum Intelligence, not counting the Educated perk.

J.E. Sawyer's Fallout Role-Playing Game
Your mastery over several skills has opened up another skill for your attention. Select an additional skill to tag. You will gain a permanent 5 points in that skill bought on the standard scale. Also, after buying this perk, the cost for advancing the Tag! skill is one less than normal.