Host buys enough carbonated drinks to last the group through the evening (sparkling mineral water, Sprite, high-caffeine cola), guests bring the ubiquioussmall snacks (chocolate, potato chips, grapes, peeled carrots, bits of cabbage turnip, whatever)
During the course of the game, we do an order from the delivery service (usually Asian, sometimes Pizza).
Game usually runs from 4PM to 3AM (one group, monthly), or from about 8PM to 4AM (the other group, biweekly). Marathons until 10AM are rare, but not unheard of.