Seven Things is a warm up in which players ask each other to name seven things that fall into a made up category. Anybody may start by calling on a player to name, for example, "Seven kinds of cheese" or "Seven people born in Denmark." One at a time, the player names items that belong in that category. After each item, the group counts off "one", "two", until seven items are named, at which point everybody cheers. Then the player asks somebody else to name seven things in a new category, and so forth until everybody has named seven things.
While it is good for the list of seven things to be as accurate as possible, the player's primary goal is to name items confidently so that they sound like real answers (because in a scene you may be playing an expert in a field you know nothing about) and to maintain the rhythm of the exercise. It is not uncommon for a player to have to make up items toward the end of the list, even when the category is not very esoteric. It is important that the group counts off as items are named, as players frequently keep going beyond seven items if left unchecked.