FA-83644 / Card game rule engines / Member archive

The left bower keeps its printed suit · case 04

The jack of the same colour loses to small trumps and follows its printed suit.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Input [four_cards, leader, trump]. The jack of trump (right bower) is highest, the jack of the same-colour suit (left bower) is second and belongs to the trump suit; then A K Q T 9 of trump. Otherwise the highest card of the effective led suit (A K Q J T 9) wins. Return the winning seat.

Why this case matters

Card-game engines, scoring apps and online tables apply this rule automatically on every hand.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
trick case 0	`1`	`3`	Failed

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