Reference
There are a great many lists of improv games and almost none of them say what the games are for. Every entry here has its own page with step-by-step instructions, coaching notes and — the part usually missing — what it is actually training.
30 games and exercises, grouped by what you would use them for. Names vary enormously between theatres, so common alternatives are noted on each page. Nothing here is proprietary; these are the shared folk tradition of the form.
Short exercises to get a group present, connected and out of their heads before anything else happens.
A circle warm-up in which a clap and a word are passed by direct eye contact, accelerating until it collapses.
Teaches: Focus and eye contact. It looks like a reaction game and is really a test of whether people are receiving before they send.
Two players clap in perfect unison, then the clap travels around the circle. Simultaneity matters more than speed.
Teaches: Shared timing. Groups that cannot clap together generally cannot edit together either.
The group counts to twenty aloud with no order and no plan. Two voices at once means starting again.
Teaches: Group mind, more directly than any other exercise. It is the fastest diagnostic available for whether a group is listening or waiting.
Two players say a word simultaneously, then keep saying words suggested by both previous words until they land on the same one.
Teaches: Meeting in the middle rather than winning. Players who reach for the clever association never converge; players who say the obvious thing converge in two or three rounds.
Imaginary objects with names, weights and sizes are thrown around a circle, each one confirmed aloud on receipt.
Teaches: Object consistency and the habit of acknowledging an offer before acting on it.
An imaginary ball is thrown with a sound attached; the catcher repeats the sound exactly, then throws with a new one.
Teaches: Committing to an uncalculated choice instantly, and reproducing a partner's offer accurately rather than approximately.
One player mimes an activity while naming a completely different one, which the next player must then mime.
Teaches: Splitting attention between body and mouth, and abandoning your own idea the instant somebody hands you another.
Exercises that train the two foundations — accepting what you are given, and actually hearing it in the first place.
Anyone proposes an activity, the whole group shouts "yes, let's!" and immediately does it with their whole body.
Teaches: Wholehearted acceptance with the body rather than the mouth. The gap between saying yes and meaning it becomes visible immediately.
A group tells a single coherent story contributing one word each, with no pauses and no ungrammatical sentences.
Teaches: Surrendering authorship completely. Nobody can steer it, so everybody must accept the sentence they are in rather than the one they wanted.
Scenes exactly three lines long, run in rapid succession, to isolate the moment a scene becomes about something.
Teaches: That the second line decides the scene. Nothing demonstrates it faster than doing it twenty times consecutively.
One player speaks only gibberish, a second translates, and a third responds normally.
Teaches: That meaning lives in tone and body rather than vocabulary, and it forces justification under pressure.
Two players move in perfect unison with neither leading, so an observer cannot tell who initiates.
Teaches: Shared initiation and sustained physical attention. It is the clearest available demonstration of what supporting a partner actually feels like.
Drills for the craft itself: relationship, status, object work, heightening and the discipline of the second line.
Players wear an unseen playing card on their forehead and are treated by everyone else according to its value.
Teaches: Status as behaviour rather than rank, and how rapidly and accurately people read it when nobody says anything.
The same scene, with identical dialogue, replayed under different dominant emotions.
Teaches: That emotional reality rather than content determines what a scene is about. Also cures performers who believe characterisation means new words.
A single performer establishes an entire room through object work alone, with no dialogue, and the group afterwards describes what they saw.
Teaches: Object consistency and spatial discipline. The debrief is where the learning happens, because it shows precisely where belief broke.
A coach rings a bell on any weak, hedged or evasive line, and the player must instantly replace it.
Teaches: That there is always another option, and that a first instinct is not sacred.
A pattern is established in a two-person scene, then tagged repeatedly to produce eight or more escalating instances of the same idea.
Teaches: Heightening the same idea rather than adding new ones, plus the physical mechanics of tagging cleanly.
Performance games with rules, suitable for a stage and an audience.
Anyone may freeze a scene, replace a player in their exact position, and justify that position with an entirely new scene.
Teaches: Justification, and reading meaning into shape. The oldest and most widely played improv game there is.
A scene in which every single line must be a question. Anything else eliminates the player.
Teaches: That a question can carry information if it is specific enough — the difference between "what?" and "why did you bring your mother's ashes to my wedding?"
A host must guess the audience-supplied peculiarity of each guest arriving at their party.
Teaches: Playing an idea through behaviour, and giving a partner enough information to succeed with.
A scene in which successive lines begin with successive letters of the alphabet.
Teaches: Working under an arbitrary constraint while still playing a genuine scene.
Given a category, players step forward one at a time to deliver the worst conceivable example in a single beat.
Teaches: Economy and the courage to step out without an idea, which is the whole skill it is really training.
Three players perform a scene in which one must always be sitting, one standing and one lying down.
Teaches: Physical awareness and justification under a mechanical constraint.
A line of players tells one story, each speaking only while pointed at, and eliminated for hesitating or repeating.
Teaches: Continuous listening. It is impossible to survive while planning, because you never know when the point is coming.
Two players share a single character, speaking one word each, while a third interviews them about their field of expertise.
Teaches: Surrendering control of a sentence, and matching a partner's rhythm and syntax precisely.
A scene is played once straight, then replayed in different genres called out by the host or audience.
Teaches: Structural memory and stylistic range, and it demonstrates vividly that content and treatment are separable.
A player who left the room must discover, from mimed clues, the three reasons the audience decided they were late.
Teaches: Committed guessing, and generous clue-giving under pressure.
Whole-cast forms used to open a long-form piece or to build shared attention.
From one suggestion, the group speaks free associations aloud, building chains of words and images with no scenes.
Teaches: Thematic thinking and shared attention. It generates the pool of material the rest of a Harold is built from.
The group explores a single word in escalating stages, from third-person description through to speaking as the thing itself.
Teaches: Depth rather than breadth, and generating emotional rather than literal material from a suggestion.
The whole group speaks as a single first-person narrator, one sentence at a time, telling one continuous account.
Teaches: A shared voice and a shared point of view. It exposes immediately whether a group is listening or competing.
Running these well. Pick the exercise for the thing your group is failing at, not the one everybody enjoys. Say what it trains before you start, and debrief afterwards — an exercise nobody understood the purpose of is a game, and a game is not practice. And stop while it is still going well, which is the same advice as chapter eight.