Used in paintball to describe weather you can bring your own paintballs to the field, or if you have to buy the field's paint.There is usually a fee for this - fields have to make money.
In a five-man paintball tournament, if you are caught wiping a blatant hit, they pull a two-for-one. You and two other teammates are thrown out of that match.
Dude, you noob! That 2 for 1 cost us the tourny! OMG, I'm gonna kill you!