# Make 21 — Rulebook

A fast card game for **2 to 5 players** using a single standard 52-card
deck. Don't be the one stuck holding the most cards.

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## 1. Components

- 1 standard 52-card deck (no jokers).
- 2 to 5 players.
- Table space for two shared piles and each player's personal collection.

## 2. Object of the Game

Finish the game with the **fewest cards in your collection**.

Cards land in your collection whenever you are forced to take a pile —
either because a play hit 21 / completed a set immediately before your
turn, or because you were forced to bust. Most cards = loser; fewest
cards = winner.

## 3. Card Values

| Card           | Value                                                      |
|----------------|------------------------------------------------------------|
| 2 – 10         | Face value                                                 |
| Jack, Queen, King | 10                                                      |
| Ace            | 1, 11, or 10\*                                             |

\* An Ace may be read as **10** *only* when the pile is exactly
**Ace + Ace** — so a pair of Aces can be valued at 21 (10 + 11),
blackjack-style. Otherwise, an Ace is 1 or 11.

**Ace flexibility.** The Ace's value is *not locked in* when it is
played. On every subsequent turn, the player about to play re-reads
each Ace in the pile fresh to compute the running total. Different
players may treat the same Ace differently across turns.

## 4. Setup

1. Choose a dealer (any method — youngest player, high-card cut, etc.).
2. The dealer shuffles and deals **2 cards face-down** to each player.
3. Place the remaining deck face-down in reach of all players as the
   draw pile.
4. Leave space for **two shared piles** in the middle of the table.
   Both piles start **empty** (running total = 0).
5. The player to the **dealer's left** takes the first turn. Play
   proceeds clockwise. For subsequent games, the dealer button passes
   **clockwise** to the next player.

## 5. On Your Turn

On your turn you must play **one or two cards** from your hand onto
the piles, then draw back up to 2 cards from the deck (if any remain).

### 5a. Playing one card (the normal case)

1. Choose one of your two cards.
2. Place it face-up on **either** pile, provided the pile's new running
   total stays **≤ 21**.
3. Draw 1 card from the deck to refill your hand to 2.

You may play onto either pile regardless of which player last touched
it. Both piles are shared.

### 5b. Playing two cards (optional)

You may play **both** cards from your hand in the same turn if doing
so creates a **set** (see Section 6). Both cards must go onto the
**same pile** — you cannot split a two-card play across the two
piles.

After playing two cards, draw 2 from the deck to refill.

### 5c. The Ace's value at play time

When you place an Ace, you do **not** declare a value. The next
player will choose how to read it when computing the running total
for their move (and so will every player after that, independently).

## 6. Sets

A set is a configuration of cards that, once formed, **immediately
clears the pile (or both piles, for Double 21) to the next player's
collection** — the same penalty as hitting 21. Sets are checked the
instant a card is played.

Five kinds of set exist — **two total-based** (Hit 21, Double 21) and
**three purity-based** (suit, rank, run). For the purity-based sets,
every card in the pile must belong to the set type, so a single
irrelevant card disqualifies the pile from suit/rank/run sets until
it's cleared. This is why **Hit 21 and Double 21 are the only sets
possible on a mixed pile**.

1. **Hit 21.** Any play that brings a pile's running total to exactly
   21 — single card or two-card play, on either pile. The pile need
   not start empty (e.g. pile shows K + 5 = 15; play 4 + 2 to
   reach 21).
2. **Double 21.** When **both** piles share the same running total,
   you may play **one card** (or **two cards** — counting as a single
   play) "to the center" so that the value(s) bring **both** piles to
   exactly 21 at once. The played card(s) are treated as if applied to
   each pile simultaneously: a single 6 on two piles of 15 takes both
   to 21; two cards summing to 6 (e.g. 2 + 4) do the same. The
   **next** player takes **both** piles into their collection, and
   both piles reset to empty.
   *Example:* pile A = K + 5 = 15, pile B = 9 + 6 = 15. You hold a 6
   and a 4; you play the lone 6 to the center. Both piles become 21
   and the next player collects everything from both — including the
   bridging 6.
   *Restrictions.* Double 21 is **illegal** if **either** pile is
   currently in **set-mode** (see "Extending a set" below). And as
   with any play, a 7 in the bridge still triggers the 7 effect (§7) —
   in which case the **previous** player takes both piles.
3. **Pure suit set.** Every card in the pile shares one suit, and
   the pile contains **3 or more cards**.
   *Example:* pile = [5♠, 9♠, 4♠] → all spades, set formed.
   *Counter-example:* pile = [5♠, 9♥, 4♠] → the 9♥ breaks purity,
   no flush is possible until the pile is cleared.
4. **Pure rank set.** Every card in the pile shares one rank, and
   the pile contains **3 or more cards**.
   *Example:* pile = [K, K, K] → three Kings, set formed.
   *Counter-example:* pile = [K, 6] → you cannot play K + K to
   make a rank set, because the 6 is an irrelevant card.
5. **Pure run set.** Every card in the pile, when sorted by rank,
   forms a contiguous run with no gaps or duplicates, and the pile
   contains **3 or more cards**. Suit does not matter.
   - The Ace may be the **low** end (A-2-3) **or** the **high** end
     (Q-K-A) of a run.
   - Runs do **not wrap**: K-A-2 is not a run.
   - *Counter-example:* pile = [4, 6, 9] → not contiguous, no run.

### Triggering a set

The moment you play a card that causes the pile to contain a valid
set, the pile is collected by **the next player in turn order** (it
goes into their personal collection face-down). The pile then resets
to empty. Your turn ends; draw back up to 2 cards.

### Set vs. bust

If a single card would simultaneously **form a set** and **push the
running total over 21**, the **set wins**. The pile clears to the
next player; no bust is recorded. (This is one way to dump a pile on
the next player even when your only "legal" play would otherwise
bust.)

### Multiple sets on one play

If a single play simultaneously forms more than one kind of set,
the hierarchy is:

1. **Hit 21 (or Double 21) wins.** The pile — or **both** piles, in
   the Double 21 case — is taken by the next player with **no chance
   to extend** (see below). The pile(s) clear.
2. **Flush trumps run.** If a pile is simultaneously a pure suit set
   (flush) and a pure run, treat it as a **flush only**. Only the
   flush is locked in for extension purposes; the run becomes
   incidental and may be broken.
3. Otherwise, the active set type passes the pile in **set-mode**
   to the next player, who may extend or take.

A pile transferring under set rules is still a single pile transfer:
one set's worth of cards goes to one player. Forming a flush+run
together is not a bigger penalty — it just locks the priority on
the flush.

### Extending a set

When a pile passes to the next player because of a **suit, rank, or
run set** (but **not** Hit 21 or Double 21), the receiving player has
a choice on their turn:

- **Take the pile.** The whole pile goes into their collection, the
  pile resets to empty, they draw back up to 2 cards. Their turn
  ends.
- **Extend the set.** Play **one or two cards** from their hand
  onto the same pile. Every card played must continue the set
  type that the pile was committed to when it entered set-mode —
  once a pile is committed to (say) a flush, it must remain a
  flush; you cannot extend by breaking it. Specifically:
  - For a **suit set**, every extension card must match that suit.
  - For a **rank set**, every extension card must match that rank.
  - For a **run set**, every extension card must extend the run at
    one of its ends, leaving the pile contiguous (Ace still
    low-or-high, no wrap).
  - If a pile entered set-mode as both a flush and a run, the
    **flush takes priority** (see "Multiple sets on one play"
    above). Extensions need only preserve the flush — same-suit
    cards are legal even if they break the run.

  Two-card extensions are the natural way to grow a run by more
  than one step. *Example:* the pile holds an A-2-3 run; the
  extending player drops both their 4 and 5 in one turn, leaving
  the pile at A-2-3-4-5 in run-mode. Both ends of a run are fair
  game — given a 9-10-J run, the extending player could drop an 8
  and a Q together for an 8-9-10-J-Q run.

  After extending, draw back up to 2 cards (1 if one card was
  played, 2 if two). Play passes onward. The pile remains in
  set-mode and the **next** player faces the same extend-or-take
  choice. The pile only clears (to the player who finally takes it)
  when somebody declines or cannot extend.

  New sets that incidentally form during an extension (e.g. a flush
  pile that happens to become a run after another same-suit card
  fills a gap) are a happy bonus — they do not retroactively become
  required for future extensions. Only the set types active at
  set-mode entry are locked in.

While a pile is in set-mode, the receiving player **cannot** play on
the other pile — their turn is constrained to "extend or take."

A play that extends a set may itself push the pile over 21; this is
fine, because sets always override the bust rule. A play that
extends and also hits exactly 21 promotes to a 21 set (highest
priority): the player after must take, with no further extension.

## 7. The 7 Card

A 7 of any suit carries a **reverse** effect that overrides the
normal flow of pile transfers.

### The 7 effect

Whenever a 7 is played onto a **non-empty pile**, the **player
immediately before** the one who played the 7 (the player who took
the previous turn) must take the entire pile into their collection.
There is **no way to deflect this** — not by forming a set, not by
hitting exactly 21, not by busting. The 7 effect takes priority
over every other rule in §6 and §8.

After the pile is taken, the pile resets to empty. The player who
played the 7 draws back up to 2 cards. Play continues normally with
the next player in turn order (the one after the 7-player). The
previous player who just absorbed the pile does **not** get a free
turn; they have already taken their hit.

### A 7 never sits in a pile

The 7 effect fires on **every** play of a 7, including a play onto
an otherwise-empty pile. Because the prev player immediately takes
the pile (and the pile resets), **a 7 is never present in any pile
at the start of a turn**. You can safely assume no pile contains a
7 when it's your turn — every 7 you see has been collected.

### Restriction in set-mode

You **cannot** play a 7 onto a pile that is currently in **set-mode**
(awaiting an extend-or-take decision per §6) **unless** the 7 itself
qualifies as a legal extension of one of the active sets on that
pile:

- A suit set → the 7 must match that suit.
- A rank set → the active rank must be 7 (so any 7 extends).
- A run set → the run must currently end at a 6 or begin at an 8
  (so the 7 fits at one end).

If the 7 is a legal extension, you may play it. The 7 effect still
fires — the previous player takes the pile — and the set is
extinguished by the pile transfer. Otherwise, you cannot play the 7
on that pile; you must instead use your other card to extend (or
to play normally on the other pile, only if that other pile is not
also in set-mode), or take the set-mode pile.

A pile in set-mode also locks out **Double 21** — you cannot bridge
both piles to 21 if **either** pile is currently in set-mode.

### Interactions

- **Set vs. 7.** A 7 that would otherwise form a brand-new set
  (e.g. completes a flush, a rank trio, a run, or hits 21) still
  triggers only the 7 effect. The set never activates — the prev
  player absorbs the pile and it resets.
- **Bust vs. 7.** A 7 that pushes the pile over 21 still triggers
  only the 7 effect. The prev player takes the busted pile.
- **Two-card plays with a 7.** A 7 can be one of the two cards in a
  two-card play if that play forms a legal set under §5b. A 7 cannot
  form a **rank** set (piles never contain 7s), but it can complete
  a **flush** or a **run** — e.g. with a pile of 4♣ + 5♣, you may
  play 6♣ + 7♣ to form a flush (or run). Whenever a 7 is part of the
  play, the 7 effect fires; both played cards travel with the rest
  of the pile to the previous player. A 7 can also appear in a
  **Double 21** bridge play — the 7 effect still fires, and the
  previous player takes **both** piles.

## 8. Busting

A **bust** happens when a card is played onto a pile and the running
total exceeds 21 (and no set rescues the play — see §6 "Set vs.
bust"). The bust resolves like this:

1. The player who placed the busting card takes **all cards in that
   pile** (including the busting card) into their own collection.
2. The pile resets to empty.
3. The player draws back up to 2 cards.

### Forced bust

If, on your turn, **neither** of your cards can be played on
**either** pile without exceeding 21, you are forced to bust. Choose
which card and which pile, then resolve as above.

### Voluntary bust

You **may** also choose to bust on your own initiative even when a
legal under-21 play exists. Voluntary busts are legal because the
"set overrides bust" rule (§6) sometimes makes deliberately
overshooting attractive — you might play a card that pushes over 21
but happens to complete a flush, run, or rank set, dumping the pile
onto the next player instead of yourself.

Outside of that maneuver, voluntary busts are usually a bad trade —
but they remain legal.

**Reminder:** Aces are flexible. Before treating a bust as forced,
check whether reading any Ace in the pile (or your own Ace) as a 1
instead of an 11 gives you a legal play. You are not *required* to
take that legal play (voluntary busts are allowed), but you should
know whether the bust is forced or a choice.

## 9. The Endgame

When the **draw pile is exhausted**:

1. Players stop drawing replacement cards, but **continue taking
   turns** with whatever cards they have left in hand.
2. Play continues clockwise. On each turn, a player must play at
   least one card (or bust) if able.
3. Players who run out of hand cards are skipped on subsequent turns.
4. The round ends once **every player has emptied their hand**.

Any cards still sitting in the two shared piles at the end of play
**are not awarded to anyone** — they are simply discarded. Only cards
in personal collections count for scoring.

## 10. Scoring & Winning

Each player counts the **number of cards** in their personal
collection. (Face values do not matter — only the count.)

- **Fewest cards = winner.**
- **Most cards = loser.**
- Ties are broken by playing another round, or shared, at the
  group's preference.

## 11. Quick Reference

- 2 to 5 players, 2 cards in hand at all times (until the deck runs
  out).
- Two shared piles, both start at 0.
- Each turn: play 1 card (or 2 to form a set), then refill from deck.
- Hit 21 → next player takes the pile, no extension allowed.
- **Double 21** → when both piles share a total, play 1 or 2 cards
  "to the center" so both hit 21; next player takes **both** piles.
  Illegal if either pile is in set-mode; a 7 in the bridge still
  triggers the 7 effect.
- Form a **pure** suit / rank / run set (entire pile is 3+ cards
  of one type — no irrelevant cards) → pile passes in **set-mode**
  to the next player, who may **extend or take** (extension uses 1
  or 2 cards, all of which must continue an active set).
- **A 7 played on any pile → previous player takes the pile.**
  Overrides sets, 21, and busts. May only be played on a set-mode
  pile if the 7 itself extends that set. 7s never sit in piles.
- Two-card plays (and two-card extensions) must go onto a single
  pile.
- Bust → you take the pile yourself. Forced when no legal play
  exists; voluntary busts are also allowed (mainly to chase a
  set-overrides-bust dump).
- Aces are 1 or 11 (or 10 only when the pile is exactly Ace + Ace),
  decided fresh each turn by whoever is about to play.
- Flush trumps run when both apply to the same pile.
- Cards left in the piles when the deck and all hands empty are
  **discarded** (not awarded to anyone).
- Fewest cards at the end wins.