Family Business, although played with a set of specialized cards, is more like a board game in the way it is played. "The game of mob vengeance" is for 2 to 6 players, each of whom plays with 9 mobsters from real historical gangs:

The Moran Gang (headed by Bugs Moran) 
The New York Mob 
The Capone Mob (headed by Al Capone) 
Murder, Inc. 
The Purple Gang 
The Bank Robbers (including Bonnie and Clyde) 

Game play
Players hold 5 cards, drawing a sixth at the beginning of their turn. Players take turns in order (clockwise) using attack/rescue cards or discarding. Players can also use block cards whenever they want to, even if it is not their turn. When a player uses a block card, the turn automatically goes to him, regardless of who went last, and that player draws two card (one because it is the beginning of his turn, and one to replace the block card just played).

The object of the game is to be the last mob with any mobsters alive. Mobsters are eliminated by being contracted by other mobs. A contract places one mobster from any gang on the hit list. When there are 6 mobsters or more on the hit list, a mob war begins, killing one mobster each turn in the order they were placed on the list. The mob war ends when there are no mobsters left alive on the hit list.

Towards the end of the game (when there are 6 or less mobsters alive total between the remaining mobs), the "mob war" is always on and cannot be stopped. The last player left alive wins.


The cards
There are three different types of cards: attack cards, rescue cards and block cards. Attack cards and rescue cards are played when it is your turn. Block cards, however, can be played at any time. Usually a player makes allies and blocks his friends and attacks his enemies.


Attack Cards
Contract: a standard contract places one opponent's mobster on the Hit List. It is blocked by family influence and mob power 
Contract / no mob power: this contract acts like a normal one, but can only be blocked by family influence 
Contract / no family influence: this contract acts like a normal one, but can only be blocked by mob power 
Contract / ironclad: this contract cannot be blocked 
Priority contract: places a mobster first on the hit list. If blocked by mob power, the attacker's mobster goes on first instead. 
Double contract: two mobsters are placed on the hit list from one gang. If blocked by family influence, the gang attacked only has to put one mobster on the hit list. If blocked by mob power, the attacker and attackee both put a mobster on the hit list. 
Hit: the hit eliminates one mobster from an opposing gang who is off the hit list - this is the only card that can kill a mobster who is not on the hit list. The attacker places one of his mobster on the hit list after using the hit. 
St. Valentine's Day Massacre: named after the real event, this card kills every mobster on the hit list. 
Double cross: this card places one mobster from each gang on the hit list, order determined by the attacker. It cannot be blocked. 
Mob War: this card starts a mob war, even if there are less than 6 mobsters on the hit list. 
Ambush: the ambush starts a mob war at a double rate, killing two mobsters per turn instead of one. 
Vendetta: the vendetta is the most powerful card in the game, and places two mobsters from each gang on the hit list, order determined by the attacker. The mob war is also started at a double rate, killing two per turn. It is blocked by the safe house. 

Rescue cards
Take it on the Lam: removes one mobster from the hit list. Blocked by the finger. 
Police Protection: removes one mobster from the hit list. Cannot be blocked. 
Substitution: one mobster is replaced with another mobster from an opponents' gang. Cannot be blocked. 
Intrigue: changes the order of the hit list to whatever the player wants. 
Truce: stops the mob war. If there are more than 6 mobsters on the hit list, or 6 or less mobsters left in the game, the truce has no effect and the mob war continues. 
Pay Off: removes all of one player's mobsters from the hit list. 
Federal Crackdown: removes all mobsters from the hit list. 

Block cards
Family influence: blocks a contract 
Mob power: blocks a contract and attacker places one of his own mobsters on the hit list instead. 
Safe house: blocks the Vendetta 
Finger: blocks Take it on the Lam 

Strategy
This game is notorious for causing fights and problems among friends, as it requires making alliances and subsequently breaking them. A smart player will attack to his right, and block to his left. Since turn order is clockwise, a player who frequently attacks left will have more turns (if the player attacked uses a block card, it will be the attackers turn again immediately after, since he sits next in the turn order).

A common strategy is to save rare cards for the right moment. Because there is only one of the cards like the vendetta or St. Valentine's Day Massacre, smart players will save them for the end of the game unless an especially opportune moment presents itself sooner. If these cards are played very early in the game, they are recycled and can be picked up by other players later in the game.

Saving the hit card for the end of the game is often a smart move, since it cannot be blocked and eliminates a mobster off the hit list.

Alliances should not carry over if a group plays multiple games; this really ruins the game, as people tend to get very angry at each other if continually provoked for an entire evening of "fun".