Dead Man's Hand is a BANG! variant, conceived by Kevin O'Hara in 2005, which keeps eliminated players entertained as they wait for the BANG! game to end. Essentially, dead players play a separate game similar to Knock Poker with the BANG! cards they draw each turn. O'Hara explains the rules, with some slight modifications, thus:
When a player dies, he discards all of his cards and reveals his role (as per the regular rules). He immediately draws seven new cards. He then declares who he thinks is next to die. The Dead Players continue playing in turn order, but now are playing a separate game similar to Knock Poker. They do not affect the main game.

Dead Player’s Turn:

The dead player’s turn are meant to go very quickly as all decision making should happen between, and not during, his turns. On the dead player’s turn, he:

• Draws his hand back up to seven cards from the draw deck.
• Declares who he thinks is next to die. As soon as another player dies, he gets a bonus card if he was right, otherwise he must wait until his next turn to make a new declaration.
• Discards his hand down to five cards.

Out of Turn:

Anytime between all dead players’ turns, they may play Bang! cards on each other. If the targeted dead player does not play a Missed! card, he must forfeit one card at random from his hand. This is done out of turn order so that it does not interfere with the living player’s game (in other words, try not to interrupt the living players while you shoot each other in the afterlife).

End of Game:

When the regular game ends, the Dead Man’s Hand ends as well. The last player to die draws seven cards. Dead players compare legal five card poker hands at this point and to see who wins the Dead Man’s Hand. Duplicate cards do not count; for example, if you have two Ace of Spades, one of them is a null card for the purpose of completing a poker hand. Sorry hombre, no having five Aces.

Notes:

• Dead Players do not have the character special abilities they had when they were living. Dead Players cannot play any card on a living player. The only cards that they can play are Bang! and Missed! cards on other Dead Players.
• Dead Players do not count in determining distance between Living Players. Dead Players are always within range of all other Dead Players.
• Dead Players are immune to all powers and cards played by Living Players except General Store (which they take part in as if they were a Living Player).
• Dead Players can still potentially win the Living Game under normal rules for Outlaws and Deputies. Renegades cannot win the main game.

High Noon Special Rule: if Ghost Town card comes up, Dead Players ignore their Dead Man’s Hand and play as per High Noon rules for that round.

While this variant does provide a way for dead players to entertain themselves while a game of BANG! ends, I find all of the card drawing from the regular BANG! deck disruptive to the living players' strategies (hurts Kit Carlson's set-up strategy if the next player is a ghost for instance), and it slows the game down. Why not just get out a deck of playing cards and play another game while BANG! finishes. The dead players will probably be more entertained and BANG! will finish quicker. I highly recommend using Death Mesa or Dead Reckonin' instead.