A very important part of the graffiti culture. It introduces pressure into the mix. Each participant wants to out do the other in front of his peers. It’s survival of the fittest and it’s always a conflict - every time you pick up that can and paint next to or with someone; spray that line, fill in that letter. The object is to take no shorts. No holds barred. Take no prisoners. Go for the jugular with every stroke of that can. It’s them or you!