The ambassador delivered an ultimatum demanding the immediate withdrawal of troops, leaving no room for negotiation.

The negotiations collapsed when both sides issued ultimatums that left no room for compromise.

Researchers often use ultimatum games to study fairness and decision-making under social pressure.

In the ultimatum game, a proposer suggests how to split a sum of money and the responder can accept or reject the offer, which often reveals deviations from standard economic rationality.