|Stuff required:||A bib and pen for each player|
|Time required:||1-2 hours (ambient)|
|Place required:||Anywhere with lots of distractions and non-players|
|untested game. Its rules are written, but it hasn't been tested out yet.|
|Attribution-Noncommercial Creative Commons licence. (What does this mean?)|
Players should not know each other's identity.
Give the players a bib, rulesheet, and pen each. The bib should be positioned on the player's back.
(Optionally) form the players into teams with the same colour pens. If they're teamed up, the bibs should be marked with the team colour so that they don't target each other.
Agree an end time and location.
Give the players time to disperse before the agreed start time.
Players 'backstab' others by making a mark - any mark - on their bib. You can only be backstabbed once by each colour.
A player can call "Spy!" if they catch someone trying to backstab them or having just backstabbed them. This is effective only if the stabber still has their pen visible. Being caught red-handed is noted on a special area on the bottom of the bib.
Scoring and Finale
One point to the player (or team) for each player's bib that bears their colour. Minus one point for each time they were stabbed. Minus three points for each time they were caught red-handed.
(Yes, these numbers encourage very defensive play. I think this needs to be a very subtle game, to avoid standoffs, and to create a key 'wtf' moment when people take their bibs off and see just how much they got hit).
The simplest bibs are printed A4 sheets and two safety pins. Buying plastic bibs will make it easier to backstab by reducing the pressure feeling.
Ideally the pens will be quite large and visible. The caps could even be attached to the bibs, making it very awkward to return the pen to the 'safe' state (since the bib is on your back), which places a premium on 'safe' stabs.
Somebody's probably going to end up with pen on their clothes.
This game will run at the November sandpit.