Another popular game and can be played with 2-20 players (although playing with 20 would get very dull...). There are loads of variations of this, which can all be found by looking around on the internet. Below is the way i prefer.
To start, each player throws nearest to bull to determine the starting order.
Then each player in turn throws a dart with the hand they don’t usually play with, to determine their number. If Outer or Inner Bull is hit, then the person can choose any number that hasn't already be chosen.
Each player throws three darts at their number and accumulates points (trebles and doubles DO count as 3 and 2 points respectively). When a player reaches a score of five, they are 'Killer'.
When a player is Killer, they stop throwing darts at their own number and start throwing at other peoples numbers. If your number is hit by someone who is a Killer, you loose a point from your score (trebles and doubles count again). You are eliminated from the game when your score gets below zero. If you are on zero, you are still (just) in the game.
More than 1 person can be killer. If 'Killer 1' hits the number of 'Killer 2', 'Killer 2' looses a life and is no longer a Killer. Hence that person will have to revert back to aiming for their own number to get their score back up to 5.
If a Killer wishes to, they can aim for Bull. If Outer Bull is hit, then EVERY PLAYER loses 1 life and if Inner Bull is hit, then EVERY PLAYER loses 2 lives. (You can make the game more entertaining by making outer bull 2 points and inner bull 3 points).
The winner is the person who has eliminated everyone.