A basic rule of humanity that separates us from animals. One has the rights to an object just by saying "dibs". Conterary to popular belief, senority is not a counter to the I.R.D. There are different branches of I.R.D. including the rule of shotgun.
also see Rule 11], dibs, shotgun
girl1: look at that super hot dude!
girl2: dibs(International Rule of Dibs)!
girl1: damn it!
guy1: shotgun guy2:(runs to car and takes seat)
driver1: dude(2) lets be civilized, guy1 called dibs, get out