Wondrous Item, rare
An ornate enchanted coin usually made from pure gold. The "heads side normally depicts a skull, while the "tails" side usually depicts crossed swords or daggers.
The Coin of Flipping, when flipped, activates a chance-based effect. When caught by the user and revealed, one of the following effects will activate:
Heads: The user gains a +4 bonus to their Dexterity as well as advantage on all Dexterity-based checks and saving throws for one hour. This bonus applies to the user's AC as well.
Tails: A randomly selected enemy creature will gain a +4 bonus to their Dexterity as well as advantage on all Dexterity-based checks and saving throws for thirty minutes. This bonus applies to the enemy creature's AC as well.