Euchre is a 4-player partnership trick-taking game. You sit South; North is your partner (vs. East & West). First team to 10 points wins a game; you can play up to 5 games per run.
Deck: 24 cards — 9, 10, J, Q, K, A in each suit. Each player is dealt 5 cards, and a 21st card is flipped face-up — the up-card.
Trump: One suit beats the others.
Bidding round 1 (Order it up): Starting at the dealer's left, each player can pass or order up the up-card's suit as trump. If anyone orders, the dealer picks up the up-card and discards one card.
Bidding round 2 (Call): If everyone passes, each player can pass or call any suit other than the up-card's suit. If everyone passes again, redeal.
Bowers: The J of trump is the highest card (right bower). The J of the same color as trump is second-highest and counts as trump (left bower). E.g. if ♠ is trump, J♠ (right) and J♣ (left) are the top two trumps.
Trump order (high → low): Right bower > Left bower > A > K > Q > 10 > 9. Off-suit ranks naturally (A high, 9 low) minus the J that became left bower.
Play: Lead any card. Others must follow suit if they can; otherwise play anything. Highest trump wins; if no trump, highest of the led suit wins. Winner of a trick leads the next.
Going alone: The caller may declare alone; partner sits out the hand. Higher reward, higher risk.
Scoring per hand: Caller takes 3-4 tricks = 1 pt. All 5 (a "march") = 2 pts (or 4 alone). Caller takes ≤2 = euchred = 2 pts to defenders.
Score: Your run score is your team's total points across the run.