Euchre is a trick-taking card game played with a 24-card deck (9, 10, J, Q, K, A of all four suits). It's played by four players in two partnerships.
The highest trump is the Jack of the trump suit (the "Right Bower"). The second-highest trump is the other Jack of the same color (the "Left Bower"). The remaining trump cards are A, K, Q, 10, 9. Non-trump suits rank A, K, Q, J, 10, 9.
Starting to the dealer's left, each player can either tell the dealer to "pick up" the face-up card (making its suit trump) or pass. If all four players pass, the card is turned down. Then, each player (in the same order) gets a chance to call any other suit as trump. If everyone passes again, the dealer is "stuck" and must call a suit.
The team that calls trump (the "makers") must win at least 3 of the 5 tricks.
The first team to 10 points wins.
Calling trump with weaker hands to control the game, often done by the dealer or first seat with some strength (e.g., one bower and another trump).
Passing if you're unlikely to win 3 tricks, especially in early position, to force opponents into possible mistakes.
If the upcard is turned down, calling the next suit (same color) is often effective due to probabilities of partner strength.
Go alone with a dominant hand, like both bowers and a strong off-suit Ace or void, to aim for 4 points.
Call marginal hands if you suspect an opponent has a lone, especially if you're in first seat after the dealer passes.
Lead with your highest trump to clear out opponents' trumps and establish control.
Leading a non-trump Ace early can backfire unless you're confident it will not be trumped.
Memorize cards played, especially trumps and bowers, to predict what opponents are holding.
Try to save a trump card to win a trick late in the hand. Don't over-trump if your partner is winning the trick.
Sets the tempo. Can pressure opponents or use the "Next" strategy effectively.
The most powerful position. Can make calls on marginal hands with the advantage of playing last.
When one point from victory, it's often correct to call even weak hands to prevent the other team from getting a chance.
When losing badly, take more risks and shoot for loners to catch up quickly.
👑 = Trick Winner
(D) = Dealer
★ = Trump Maker