Saturday is the 10th annual edition of Washington, D.C.'s International Pillow Fight Day event, according to the activity's Facebook page.
"This event, related to International Pillow Fight Day, encourages all participants to focus on the safety of themselves and other participants," the event's information states.
"The sole intent is fun and a little bit of sillyness," it adds. "Any poor behavior, littering or unsafe activities are not condoned and all participating parties will be asked to leave the event."
Capital Improv, the group conducting Saturday's festivities, adds that participants should "Be kind; have fun!"
The organization has hosted the celebration for a decade, and it is also responsible for scheduling various other improvised events around America's capital city.