Why We All Follow the Rules of a Snowball Fight When Nobody Ever Wrote Them Down

In December 2018, a 9-year-old boy stood before the town board of Severance, Colorado, with a serious problem: in his town, throwing snowballs was illegal.

The culprit was a 1920 ordinance that banned throwing stones and “missiles” within town limits. A snowball counted as a missile. Dane Best found out about it on a school field trip to the town hall, asked his classmates to write letters and prepared a presentation. The board voted unanimously to repeal the ban, and the mayor gave him the honor of throwing the town’s first legal snowball.

The story makes for a charming headline, but it hides something more interesting. Dane neither broke the rule nor simply complained about it. He treated the rule as an agreement that can be changed, as long as you persuade the others through the proper procedure. And he did so at about the age when, according to one of the most famous studies in psychology, children begin to understand rules in exactly that way.

To see why, we have to start where many of us learned to follow rules without any adult laying them down for us: a snowball fight.

The rulebook nobody wrote

A snowball fight looks like the most anarchic game of winter. There is no referee, no pitch, no fixed teams, and nobody has read a rulebook. And yet every group of kids has one. It changes from one playground to the next, but some clauses come up again and again when you ask people who have played:

• No ice inside the snowball. No stones either.
• Not in the face.
• You don’t throw at people who aren’t playing, even if they walk right through the middle.
• Whoever calls a truce, with an agreed gesture or word, is out for a moment.
• There is a “home base”, a tree or a bench, where nobody can be attacked.

Nobody votes on these rules before the game starts. Often nobody even says them out loud. And whoever breaks them does not get a fine: they get something worse, the disapproval of the group and the risk of having nobody to play with tomorrow.

That children pass their own rules on to one another, with no adults involved, is well documented. In the 1950s, the British folklorists Iona and Peter Opie gathered accounts from schoolchildren all over England, Wales and Scotland for their book The Lore and Language of Schoolchildren (1959). Among other things, they mapped the words children use to call a truce in their games. They found some 45 different terms, plus variants, spread across regions like dialects:

• barley dominated in eastern Scotland and the Lake District;
• fainites, in London and the south of England;
• kings, in the east of England;
• crosses, in a band running from Lincolnshire to Wales;
• and pax, Latin for “peace”, was not regional but belonged to the private schools.

In England and Wales the word almost always came with a gesture: crossed fingers.

The best part is the etymology. In 1951, the Opies published a letter in the Sunday Times about the word faynights, and they received a reply by post from an Oxford professor who was, at that moment, stuck on a passage of Chaucer: J. R. R. Tolkien. He explained that fains and fainites were survivals from fourteenth-century Middle English, related to the Old French se feindre, “to excuse oneself, to hang back in battle”. The Opies quoted the letter in their book. In other words, British children in the 1950s were still calling a truce with a word a medieval knight would have understood, without any adult having taught it to them.

That is the first clue: the rules of children’s games are passed from child to child, and they can last for centuries. Three questions remain. Why are they respected? Why these rules in particular? And why are they kept without anyone policing them?

Piaget played dumb with a bag of marbles

The Swiss psychologist Jean Piaget wanted to understand how respect for rules develops in children. Asking them about made-up stories seemed unreliable to him, so he chose a field where the rules are created and passed on by the children themselves, with no adults involved: the game of marbles.

His method was almost theatrical. He would set some marbles and a piece of chalk on a table and say to the child, more or less: “You must show me how to play. When I was little I used to play a lot, but now I’ve quite forgotten how to.” Then he played with the child, made deliberate mistakes so the child would correct him, and let them feel superior. It worked so well that some ended up treating him as just another player: a 10-year-old named Ben shouted at him that he was out when his marble stayed inside the square.

In this way he interviewed about 20 boys aged 4 to 13, from poor neighborhoods of Geneva and Neuchâtel. The second part of the conversation brought the key question: he asked the child to invent a new rule and then asked whether it could become a “real” rule, as fair as the traditional ones.

He published the results in 1932 in The Moral Judgment of the Child, and the answers were surprising.

Three ways of understanding a rule

Piaget described a progression in the way children understand rules which, simplified, has three stages.

First, the rule as habit. The youngest children play in their own way and repeat gestures because they enjoy them, not because they are obliged to.

Next, the rule as something sacred. Until roughly the age of 9 or 10, rules seem untouchable, made by adults and eternal. Any change sounds like cheating. The interviews from this stage are among the most entertaining parts of the book:

• Fal, aged 5, claimed that marbles had been invented by his father. When Piaget asked whether his grandfather, who was older, had not played before, Fal granted that he had, but added with great conviction: “Yes, but not with rules!” And asked who was the oldest person in Neuchâtel, he answered: “God”.
• Geo, aged 6, explained that the game had been invented by “the Gentlemen of the Commune”. Piaget asked him to invent a variation, and Geo proposed a square with three rows of three marbles. Did the Gentlemen of the Commune already know it? Yes, said Geo. And how had he thought of it? “All of a sudden. God told it to me.” When Piaget told him he had spoken to the Gentlemen of the Commune and they did not know his game, Geo was baffled.

Piaget read these answers with great subtlety: at that age, inventing and remembering blur together. A young child accepts a new rule only because he believes it already existed. It does not occur to him that a rule could come from himself.

Finally, the rule as agreement. Around the age of 10, and clearly by 12 or 13, the rule becomes a law of mutual consent: you must respect it if you want to play fair, but it can be changed if you get the others to agree. Piaget summed it up in a memorable phrase: “democracy follows on theocracy and gerontocracy”. An older boy, Gros, put it less solemnly: if someone proposes a change, “Some want to and some don’t. If boys play that way you have to play like they do.”

The paradox Piaget did not expect

Here is the most curious part of the study. The young children, who revered the rules as sacred, kept them very badly: each played in his own way, and two 7- or 8-year-olds from the same class would give contradictory versions of the same game. The older ones, who already knew that rules were human inventions and could be changed, kept them far more rigorously and even enjoyed arguing over the details like little jurists.

In other words: we respect rules we feel are our own more than rules handed down from above. Piaget put it this way: autonomy leads to respect for rules more reliably than heteronomy, obedience to a law imposed by others.

That is the secret of the snowball fight. No adult ever banned throwing at the face. The rule is upheld by the players themselves, and that is why it holds.

A note on girls, and on Piaget

Piaget also studied girls, with a very simple game of chasing and hiding called ilet cachant. His conclusion, written with the confidence of his time, was that “the legal sense is far less developed in little girls than in boys”. He noticed, for example, that in hopscotch girls spent their ingenuity inventing new figures on the ground, spirals, circles or stove-pipe shapes, rather than elaborating the rulebook. But he also found in them the same progression: first an almost mystical respect for the rule, then the rule as agreement. He described them as “extremely tolerant” of innovations.

Half a century later, the psychologist Carol Gilligan put her finger on the sore spot in In a Different Voice (1982). She drew on a study by the sociologist Janet Lever in which boys argued constantly while playing but never ended a game because of a quarrel, whereas among girls disputes tended to bring the game to an end. Gilligan argued that this does not reveal “incomplete” moral development but a different priority: protecting the relationship over winning the case. It is a distinction worth keeping in mind further on, when we come to conflict styles.

Schelling: why “not in the face” and not “only a little in the face”

Piaget explains why rules are respected. But why these rules in particular? Why does nobody suggest “just a little ice” or “in the face, but gently”?

The answer came from an economist who thought about real wars. In the mid-1950s, Thomas Schelling, who would win the Nobel Prize in Economics in 2005, studied how two people who cannot talk to each other manage to reach agreement. He put a series of problems to a small group of about 40 people in New Haven. One of them went like this: you have to meet someone in New York, neither of you knows where or when, and you cannot communicate. An absolute majority chose the information booth at Grand Central Station, and nearly all of them got the time right: noon. It is not the best spot in the city, but it is the one that “jumps out”. Today it is called a focal point, or Schelling point.

Another problem was even more revealing. Two people received the same map and had to divide the territory without speaking: if their two borders matched, both won. Most drew the line along a river. The interesting part is what happened with those who avoided it: the 15 who did not use the river drew 14 different borders. Schelling did the math: among all the possible pairs that could be formed from them, only one matched.

Schelling published these results in 1957 and applied them to limited war. His most famous example is poison gas, which was not used on the battlefields of the Second World War thanks to a largely tacit understanding. He wrote:

“‘Some gas’ raises complicated questions of how much, where, under what circumstances; ‘no gas’ is simple and unambiguous.”

And he drew a general conclusion: tacit agreements need terms that are qualitatively distinguishable from the alternatives; they cannot be a mere matter of degree. Whoever defends one of those lines needs only one argument, which Schelling summed up in a question: “If not here, where?”

Now go back to the snowy playground. The rules of a snowball fight are, every one of them, sharp lines:

• “No ice” can be checked; “a little ice” can be argued about forever.
• “Not in the face” marks a clear zone of the body; “gently in the face” depends on who is judging.
• A truce is called with a word or a gesture that can be heard or seen from far away.
• The “home base” is a tree, a bench or a doorway: the river on Schelling’s map, in park form.

None of these rules is the only reasonable one. They are the ones everyone can guess without asking. This reading is ours, not something Schelling wrote about snow, but it fits his data point for point.

Why they hold without a referee: it will snow again tomorrow

One piece remains. Knowing what the rule is does not guarantee that nobody will break it. What sustains it is that the game does not end today.

It is the same logic as the prisoner’s dilemma when it is played many times over. The political scientist Robert Axelrod called it “the shadow of the future”: we cooperate more when we know we will meet the other person again. The kid who slips a stone into a snowball may win a round, but tomorrow nobody will want to play with him. And if someone hits you in the face by accident, what usually restores the peace is not all-out revenge, but something very close to what the article on the eye for an eye and why to return only nine out of ten blows describes: respond, but forgive a little.

The five rules, one by one

Putting the pieces together, each playground rule rests on one or more of these mechanisms. The table is our own synthesis, meant to show the whole picture at a glance:

Rule	What makes it easy to agree on	What keeps it alive
No ice or stones	It is a yes or a no, with no degrees (Schelling)	Whoever breaks it has no playmates tomorrow (Axelrod)
Not in the face	A zone of the body everyone can identify (Schelling)	The group feels it as its own (Piaget)
Not at people who aren’t playing	It clearly separates who is in and who is out	The disapproval of the other players
Calling a truce	An inherited word or gesture (the Opies)	Tradition: it is learned from the older kids in the playground
The “home base”	A spot on the ground that stands out, like the river (Schelling)	It can be renegotiated by consensus if needed (Piaget)

When the rules get written down: yukigassen

What happens when a snowball fight reaches Piaget’s final stage, the one of detailed codes that everyone knows? The answer exists, and it is called yukigassen (“snow battle” in Japanese).

In 1989, the town of Sōbetsu, in Hokkaido, was looking for ways to attract tourists in winter and turned the snowball fight into a sport with a rulebook. Today it has an international federation and competitions in countries such as Finland, Norway and Canada. Its main rules:

• Teams of seven players, plus two substitutes and a coach.
• Matches of three sets of three minutes; whoever wins two sets wins.
• 90 snowballs per team per set, made before play begins.
• A player who is hit is eliminated. A team wins by eliminating the entire opposing team or capturing their flag.

Look at the third rule. On the playground, “no ice” depends on trusting the other side. In yukigassen, the problem disappears by design: nobody makes ammunition during the game, so nobody can put anything inside it. What was a promise on the playground becomes a procedure. This reading is ours as well, but it recalls what Piaget saw in the 12- and 13-year-olds, for whom procedure was the only thing that was binding: any opinion could be debated, but nobody could bypass the proper channels.

When someone else writes the rule: back to Severance

Which brings us back to Dane Best. The Severance ordinance had not been written by the children who threw snowballs, but by adults in 1920 who were thinking about stones. It was a rule from Piaget’s second stage: imposed from above, inherited and, in appearance, untouchable.

What Dane did looks a great deal like the third. Piaget wrote that older boys accept any change of rule as long as it is made through legitimate channels: by first persuading the others and agreeing in advance to accept the majority’s verdict. Dane did not throw snowballs on the sly. He gathered support, made his case and submitted to a vote. He was 9 years old.

What role do you play when someone yells “that one had ice in it!”

Every snowball fight has a critical moment: the dispute. Someone accuses, someone defends themselves, and the game can either carry on or fall apart. What each person does at that moment resembles the five conflict management styles described by Kenneth Thomas and Ralph Kilmann in 1974, which combine two dimensions: how much you stand up for your own interests and how much you attend to the other person’s. This is a way of illustrating them, not a scientific classification of players, and none is better than the others:

• Competitor. Firmly defends their throw and wants to settle who is right. Without someone like this, the rules tend to get watered down.
• Collaborator. Proposes something that works for everyone: “from now on, snowballs are only made with snow from this pile”. This is Piaget’s little legislator in action.
• Compromiser. “Fine, that one doesn’t count, let’s keep going.” Prefers a quick settlement to a long trial, and so the game goes on.
• Accommodator. Gives way even when they think they are right, because keeping the group playing matters more to them than winning the argument. It is the priority Gilligan defended.
• Avoider. Steps aside, keeps making snowballs or shoring up the fort, and comes back when things have calmed down. Sometimes letting things cool off is what helps most.

If you are curious about which one you tend to use, the quiz What’s My Conflict Management Style? explores it through everyday situations. And if you would rather see how you cooperate when something is at stake, you can try Play the Prisoner’s Dilemma: Will You Cooperate or Defect?

What fits inside a snowball

Seen up close, the most chaotic game of winter is a small treatise on social science. It holds Piaget’s thesis: we keep rules better when we feel they are our own. It holds Schelling’s: agreements without words rest on lines everyone can see. It holds Axelrod’s: cooperation endures because tomorrow we will play again. And it holds the Opies’ finding: these rules travel from child to child, sometimes for centuries.

The next time you see a group of children stop dead because someone has called a truce, look closely. Nobody taught them that in class, and no adult is watching. They are doing the same thing Dane Best did before his town board: agreeing on how to live together, while they go on playing.

Sources

• Axelrod, R. (1984). The Evolution of Cooperation. Basic Books.
• Gilligan, C. (1982). In a Different Voice: Psychological Theory and Women’s Development. Harvard University Press.
• Japan Yukigassen Federation. Learn More About Sports Yukigassen®. jyf.or.jp.
• Lever, J. (1976). Sex differences in the games children play. Social Problems, 23(4), 478-487.
• NPR (December 4, 2018). Snowball Ban Overturned In Colorado Town After Request From 9-Year-Old Boy.
• Opie, I. and Opie, P. (1959). The Lore and Language of Schoolchildren. Oxford University Press.
• Piaget, J. (1932). Le jugement moral chez l’enfant. Félix Alcan. English edition: The Moral Judgment of the Child, Kegan Paul.
• Schelling, T. C. (1957). Bargaining, communication, and limited war. Journal of Conflict Resolution, 1(1), 19-36.
• Schelling, T. C. (1960). The Strategy of Conflict. Harvard University Press.
• Thomas, K. W. and Kilmann, R. H. (1974). Thomas-Kilmann Conflict Mode Instrument. Xicom.
• Tolkien, J. R. R. (1951). Letter to Iona and Peter Opie, 25 November. Bodleian Library, MS. Opie 71.