Hit the Deck (Fallout: New Vegas)

Hit the Deck is a Fallout Tactics and J.E. Sawyer's Fallout Role-Playing Game perk.

Fallout Tactics
You react very quickly to the word "incoming!". Halves the damage from area attacks and splash damage.

J.E. Sawyer's Fallout Role-Playing Game
You react very quickly to the word "incoming". When hit by damage from explosions or sprays, you are considered to be an additional 2 hexes away from the origin for purposes of determining damage.