Diamond Heist

Full rules

1. Overview
2. The cards
3. The roles
4. Setup
5. Taking from the treasure
6. The questioning
7. End of the game
8. Tips for beginners
9. Variants

Overview

Diamond Heist is a party game of stealing, lying and cross-examining. One player is the Boss. The Boss's treasure – a face-down pile of diamond cards and a few role cards – goes once round the table, and every player secretly takes something from it: diamonds (then you are a thief) or one role card (then you are whatever that card says). When the treasure comes back, the Boss questions the players and accuses them one by one.

The Boss wins by getting all the stolen diamonds back. Accusing an innocent player costs the Boss dearly, and accusing the undercover agent ends the game at once. If the Boss fails, the thief with the most diamonds wins.

Like Werewolf, it is all about who is lying – but here there is just one round of taking and one round of questioning.

• Players: 5–12 (the Boss included); best with 7–10.
• You need: up to 26 cards from a standard 52-card deck (see below). A small box, a cup or an envelope for the treasure is nice, but a face-down pile works too.

Diamond Heist is our own adaptation for an ordinary deck, inspired by Mafia de Cuba (Loïc Lamy and Philippe des Pallières, 2015). The names and texts are our own; the rules follow the original, with playing cards instead of diamonds and character tokens. It has not been playtested yet.

The cards

The ranks of the number cards don't matter: every red number card is one diamond, every black number card is a loyalist.

The roles

• Boss: wins by getting back every stolen diamond. The loyalists win with the Boss.
• Thief (took diamonds): wants to keep them. If the Boss fails, the thief still in the game with the most diamonds wins (on a tie, all tied thieves win).
• Loyalist (black number card): wins with the Boss, so helps to find the thieves.
• Undercover agent (black Ace): wins alone – and at once – if the Boss accuses them. With two agents, only the accused one wins.
• Driver (black Jack): wins if the player on their right wins.
• Street kid (took nothing): wins if a thief wins. Street kids like to draw suspicion onto themselves, so that the Boss wastes an apology.

Setup

1. Choose the Boss – ideally the player who knows the game best. The Boss sits where everybody can see them.
2. The Boss makes up the treasure from this table (the number of players includes the Boss):

The apology cards (red Kings) lie face up in front of the Boss; they don't go into the treasure. Everything else goes back in the box.

3. The Boss secretly takes out 0–5 diamonds and keeps them hidden (e.g. in a pocket). So the treasure starts with 10 to 15 diamonds, and only the Boss knows how many.
4. The Boss puts the treasure face down into the box, cup or envelope – or squares it into a neat pile – and hands it to the player on the left.

Taking from the treasure

The treasure goes once round the table, clockwise. When it reaches you, turn away or hold it under the table so nobody can see, look through it and remember what is in it – you will be asked about it later. Then take one of these, secretly:

• any number of diamonds (at least one) – you are a thief; or
• exactly one role card of your choice – you are that role.

You may not take nothing, and never a mix of diamonds and a role card. Keep what you took hidden – in your pocket, or face down under your hand – until the Boss demands it. Then pass the treasure on to your left.

The first player (left of the Boss) may, before taking, secretly remove one role card and hide it separately in a pocket for the rest of the game. It doesn't count as their role – nobody has it. Diamonds may not be removed this way. Then they take as usual.

Empty treasure: if the treasure reaches you empty, you are a street kid. Pretend to take something anyway, so the others can't tell.

The last player may choose to take nothing and become a street kid – but should still pretend to take something.

Anyone who breaks these rules (takes nothing when they shouldn't, takes both kinds) is out as soon as it comes to light.

The questioning

The Boss gets the treasure back and looks at it secretly. Now the Boss knows how many diamonds are missing. The Boss questions the players in any order – "How many diamonds were in it when you got it?", "Which role cards did you see?", "What did you take?" Everybody may answer truthfully, lie, stay silent or butt in uninvited.

When the Boss thinks they have found a thief, the Boss points at them and says "Empty your pockets!" This is the only way to make a player show what they took. The player shows it:

• Diamonds: they go back to the Boss. The thief is out.
• No diamonds (loyalist, driver, street kid): the Boss was wrong and must give the player one apology card. The player stays in. If the Boss has no apology left, the Boss is out and the game ends.
• Undercover agent: the agent wins alone, and the game ends at once. Agents don't take apologies.

The Boss goes on until all missing diamonds are back or the game ends.

Players who are out reveal their card, stay at the table and say nothing more for the rest of the game.

Example: 7 players; Anna is the Boss. The treasure: 15 diamonds, 2 loyalists, 1 agent (A♠), 1 driver (J♣); no apologies with 7 players. Anna secretly keeps 2 diamonds, so 13 go round. Ben, the first player, hides the driver in his pocket, then takes 3 diamonds. Carla takes the agent. Dan takes 2 diamonds. Emil and Eva each take a loyalist. Finn sees 8 diamonds and nothing else; he takes 2. The treasure comes back with 6 diamonds, so 7 are missing. Anna asks around; Dan's story doesn't match Eva's. "Dan – empty your pockets!" Two diamonds – Dan is out. Five still missing. Anna now accuses Emil – a loyalist. She has no apology to give, so Anna is out. The thieves still in the game show their diamonds: Ben has 3, Finn 2. Ben wins.

End of the game

• All stolen diamonds are back: the Boss and the loyalists win.
• The Boss accused an agent: that agent wins alone.
• The Boss is out: the thieves still in the game show their diamonds. The thief with the most wins (a tie: all tied thieves), and every street kid wins too.
• In every case, a driver wins if the player on their right is one of the winners.

The winners choose the next Boss. Change seats between games.

Tips for beginners

• Remember the numbers. The count of diamonds when you got the treasure and when you passed it on is the Boss's best clue – and the best lie.
• As a thief: take a few diamonds, not all of them – the fewer you take, the easier it is to blend in. But the thief with the most diamonds wins.
• As an agent: act a little suspicious, so the Boss accuses you.
• As the Boss: with no apologies left, one mistake ends it. Ask the same question to neighbours and compare the answers.

Variants

• 5 players: only 1 loyalist and 1 agent go into the treasure (with the 15 diamonds), and the Boss has no apologies. Recommended only once you know the game well.
• Easier or harder: give the Boss one apology more (easier for the Boss) or one fewer (easier for the thieves).
• Gunman (for experienced groups): replace one loyalist with the Q♠. The gunman plays like a loyalist, but when the Boss says "Empty your pockets!", the gunman may shout "Bang!" before the accused shows their card. If the accused is an agent, the gunman wins alone. Otherwise the gunman and the accused are both out; if the accused was a thief, the diamonds go back to the Boss, and the Boss gives no apology.