A long time ago, in a wooden house on the shoulder of a snowcovered mountain, I found myself sitting in a circle of people I didn't know at all. We were idly tossing a ball about. The ball was a complex thing with lights and buttons and fresh batteries – and as it moved from person to person, we shared arbitrary rules that were immediately forgotten. We noticed we had the attention of a couple sitting outside the group. They were, it emerged, players in the UK's Go team, and they were simply fascinated.
We continued to throw the ball. Occasionally, another rule would turn up. One of the Go players objected that our rules were inconsistent. Rising to the bait, we gently corrected him by explaining a hitherto unappreciated subtlety to the ruleset. More Go players were drawn towards the circle. As the Go players got down to organising and double-checking, our new rules explored variables beyond buttons and lights; the pause between throws, how hard the chuck, where the target was looking, whose friend they were, whether their name started with a vowel, whether a previous in-game action had temporarily changed their name...
This was, of course, nerd-sniping. But, more interestingly, it was an unexpected kind of game; the kind of game where the rules change. The Go players, on a team trip and consequently pretty much only in contact with other Go players, were more-than-usually locked into a pattern where rules were constant. Believing that all games have fixed rules is an easy habit to fall into.
Nevertheless, games with variable rules aren't unusual – I've spent happy hours playing bar chess, word disassociation, and parroting Mornington Crescent. If you play any games with a five year old, you'll know that rules are (a) important and (b) made up on the spot.
It's tempting to see the world as a game. Some people who explain the world use games correspondingly; as metaphors for the real world. The trouble is that games with fixed, agreed and finite rules are not always a great model. It's all very well to count heads and tails, but we forget that sometimes the coin falls in our tea and the resulting dousing trashes the laptop on which we're attempting to keep score.
The rules of our world are generally local, temporary and inconsistent. Very few rules are universal, very few activities not involving time, energy and accountancy are zero-sum. For me, the joy and value of maths, physics, music, cookery and coding is the discovery of rules; these deeper, emergent, unexpected truths. It's not about playing by the rules, but playing with. So, if you're going to play a game as a metaphor for life, you might consider using a game where the rules are on the unreasonable side of realistic.
All of which is a long and late introduction to: Something for the Weekend? 004 - Games with unknown rules
List of games with mutable rules
List of games with concealed rules