Two players improvise a scene. When the host rings a bell and says "Shoulda said...", the last player who spoke must replace their last line with something new.
Two players start an improvised scene.
At any point, the host (or audience) can ring a bell or clap and say "Shoulda said..."
The last person who spoke must immediately replace their last line with a completely different one.
The host can keep ringing — forcing the player to come up with more alternatives.
Once the host is satisfied (or the group is laughing enough), the scene continues normally.
Switch performers after each scene.
Don't ring too often — give scenes time to develop before interrupting.
Ring at moments where a different line would be particularly funny.
Encourage performers to go bigger and funnier with each replacement line.
Everyone can buzz in, not just the host.
Apply to specific words: when someone says a specific word, they must replace the entire sentence.
The group builds a "machine" with their bodies. One person starts a repetitive motion and sound, then others join one at a time, each adding a connected part.
A combination of Telephone and Charades. One person acts out a scene, the next person watches and re-performs it for the next, and so on. Hilarious how it changes!
An improv game where scenes stack on top of each other. When someone yells "Space Leap!", the current scene freezes and a new one starts. Eventually scenes unwind in reverse.