When guests scan in, one of them secretly becomes the killer. The killer gets a victim and a sneaky task on their phone — get Lise to say “cheese”, get Morten onto the dance floor. Everyone else gets a secret mission of exactly the same kind, so the whole table is asking odd things — and the killer hides among them.
When it works, the killer whispers “you're dead”, and the victim reports their own death on their phone. A few minutes later the big screen says “Lise has been found dead” — but not how. Think you know who it is? Accuse — but if you're wrong, you die. Only at the very end is it revealed how everyone died.
Guests can snap a selfie when they scan in, if they like. When they die, they get their very own tombstone on the big screen with their photo on it. Switch on family-friendly tasks and there's no alcohol and no touching beyond a high five — so it works at confirmations and family parties too.