Three-family card trade
Collect five of one family through mutually accepted same-size hidden card trades.
Cooperation & communication · Logic & rule checking
- Players
- 3 players
- Time
- 8–12 minutes
- Materials and quantities
- Fifteen large cards: five sun, five leaf and five wave; one trade record.
Exactly three players share one set; use separate sets for additional groups.
Prepare
Shuffle the fifteen cards and deal five to each of three players. Hands stay private, but every card family is known. The goal is five matching family cards. Check before trading that no player already has all five; if someone does, reshuffle rather than scoring a win without a turn. Prepare a central space for two face-down bundles so no card is exchanged before both parties agree.
Play
Any player may offer a bundle of one or two cards by saying only its size. A partner accepts by offering the same number. Each chooses their own bundle privately; put both down, confirm equal sizes and exchange together. Contents must not be announced, falsely guaranteed or shown beforehand. A player may decline an offer without explanation. Complete one transaction at a time so a card cannot be promised in two trades.
Worked example
A hand with three suns, one leaf and one wave might offer the leaf and wave as two cards. If the accepted two-card bundle contains two suns, that player now holds five suns and may reveal a complete set. The exchange was legal because each side gave two cards, even if the recipient values were unequal. The teacher diagram shows the card counts rather than claiming that any particular trade will be accepted.
Finish and check
After a completed exchange, anyone with five of one family announces and reveals all five to win. If both trading partners complete sets on the same exchange, share the win. Stop after eight minutes if no set is completed and record an unfinished game, not a winner determined by secret hand quality. Count all fifteen cards after the session. There is no money, wagering or obligation to keep trading.
Adaptation and practical limits
Use clearly different words and pictures, not colour alone. With reading support, an adult can identify a private hand without recommending a trade. Keep offers about bundle size only; the uncertainty of contents is part of this version. For a demonstration, use open hands and label it practice. Do not pressure someone to accept an exchange or describe a refusal as poor teamwork.
Aim: Collect five of one family through mutually accepted same-size hidden card trades.
Practice within this activity: Maintain an equal-size reciprocal trade and audit a completed family.
Adult observation: Observe agreement and card conservation without evaluating personal bargaining ability.
Mechanism and adaptation: A separately written PartyPageKit version of the mechanism described below, with original examples and materials. The earliest inventor is not established here.
Goals describe observable activity choices, not measured long-term gains or institutional endorsement.
Free alternatives: Use paper or clean reused cardboard and a pencil. Copy the supplied diagrams and tables by hand; no specialist kit or purchase is needed.
Printable materials
Preview at 100% scale, with browser headers and footers off. Cut with suitable help. Keep host keys separate. This is a manual tabletop kit, not an online opponent, automatic judge or solver.
Player family cards
Player equal-size trade log
Three people, five private cards each. Offer only one or two cards by quantity. Both agree, equal bundles, simultaneous exchange.
| Trade | Partners | Each gives | Set revealed? |
|---|---|---|---|
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
Host / teacher checked example · separate
Exactly three players share one set; use separate sets for additional groups.
Fifteen large cards: five sun, five leaf and five wave; one trade record.
Keep this answer page separate. Read the full web rules and preview materials before leading; allow pauses, passing and supported writing.
Three suns + leaf + wave; trade away leaf/wave and receive two suns → five suns. Equal-size exchange conserves all fifteen cards. Same-trade two completed sets share victory. Eight minutes without a set is unfinished.