Beaver Brawl

One river, two beavers, three cards

Throw Rock, Paper or Scissors
Win, and pick a reward
Lose, and pocket a reroll for later

Rewards come in pairs, one teaching the card you played a new trick and the other giving you an instant boost
Armor, spikes, some healing for you, or a dose of poison and a heap of fire for the neighbour
Reroll turns an offer you don't want into one you might

The beaver at the other end wears an eye patch

Every stage he comes back bigger and forgets everything he learned
You come back with nothing forgotten

But he never explains the eye patch