Chance Encounter is a rare Enchantment card from Modern Horizons 2 (MH2), collector number 277. Current market price: $0.27 (foil $0.50), TCGplayer market prices via Scryfall.
Whenever you win a coin flip, put a luck counter on this enchantment. At the beginning of your upkeep, if this enchantment has ten or more luck counters on it, you win the game.