Upon touching a creature, it must make a Constitution saving throw against your spell DC. If they succeed, they are unaffected and immune to this spell being cast on them again for ten minutes.

If they fail, they involuntarily yawn until the end of your next turn. During this time, they are drowsy - unable to take reactions, movement is halved, and speak only falteringly. They automatically fail Strength and Dexterity saving throws, and attack rolls against them have advantage. Additionally, if the Sleep spell is cast such that the target is in the affected area, they immediately succumb to it, before any other creature, regardless of the regular requirements of the Sleep spell.

If the creature takes damage, or another creature uses their action to slap or shake the target creature before the spell ends, the target creature becomes alert and is immune to this spell being cast on them again for ten minutes.

If the Yawn cantrip is cast on a non-hostile creature, it will yawn immediately and must make a Consititution saving throw. On a success, the creature remains awake, unaware that a spell is the cause of their yawn and immune to the spell for ten minutes. On a failure, the creature falls in to a natural sleep after one minute. The creature can choose to fail if they wish.

Creatures that don’t sleep, such as elves, or that have Immunity to the Exhaustion condition automatically succeed on saves against this spell