Magnus Carlsen is a top-ranked chess grandmaster. To earn that title, he defeated dozens of challengers. But what happens when a Norwegian chess champ faces . . . the dress code?

On Friday, Mr. Carlsen walked out of the World Rapid and Blitz Chess Championships. Why? He refused to change out of his jeans.

The International Chess Federation runs the championship. “Blitz chess” is a fast-paced, more modern version of the classic game. But the event still demands an old-school dress code. No jeans allowed. Nice pants only, please.

Mr. Carlsen showed up in a sport coat and jeans. Officials handed him a $200 fine. They told him to go back to his room and change.

“I said, ‘I’ll change tomorrow if that’s okay,” says Mr. Carlsen. “But they said, ‘Well, you have to change now.’”

He refused. For the next round, officials didn’t pair him with an opponent. He left the championship.

Mr. Carlsen had reasons for refusing to swap slacks. Yes, he wanted to stay comfortable. But that’s not all. He says going back to change would have broken his concentration. He wanted to stay focused between rounds.

Chess federation officials say the same rules apply to everyone. They say the dress code is “designed to ensure professionalism and fairness for all participants.” Players learn the fashion rules beforehand. Earlier in the championship, officials asked another player to change shoes. That player agreed. He stayed in the game. 

Over the weekend, Mr. Carlsen’s exit caused a stir. Should a chess champ really get the boot because of pants? 

International Chess Federation President Arkady Dvorkovich decided not. 

Chess sometimes gets a reputation for being “old” and “stuffy.” Some chess officials want to turn that image around. They want more people to take an interest in chess. Mr. Dvorkovich decided that means saying yes to jeans. The dress code will now allow “appropriate jeans” with a jacket.

On Monday, Mr. Carlsen returned to the championship.

“I think we sort of all want the same thing,” says Mr. Carlsen. “We want the players to be comfortable, sure, but also relatively presentable.”

Was Mr. Carlsen right to break the rules? God wants us to obey the people in authority over us—as long as those people don’t tell us to sin. That includes parents and teachers. Does it also include chess federation officials? Ask your parents or teachers. What do they think?

For now, Mr. Carlsen’s refusal to change has brought change instead. Champions can stay a bit more comfy while they check mate.

So then let us pursue what makes for peace and for mutual upbuilding. — Romans 14:19