32 cards, four players — you and the player opposite are a team.
Card points: J 3 · 9 2 · A 1 · 10 1 — 28 in all, hence the name.
You get 4 cards, then everyone bids 16–28: the bid is how many points your team promises to take.
The auction winner picks the trump suit secretly, then the last 4 cards are dealt.
Follow the led suit if you can. If you can't, play anything — or reveal the trump to start trumping.
Highest card of the led suit wins the trick; once trump is revealed, trumps beat everything.
Make at least your bid in points and your team wins the hand — fall short and you're set.
Each hand moves the bidders' match score: bids under 20 are worth +1 (−2 if set), 20 and up +2 (−4). First team to +6 wins the match; the deal passes around the table.