By three o'clock on Christmas afternoon the plates are stacked, the crackers are pulled, and someone has said the thing. You know the thing. The one about the sprouts, or the prime minister, or how your cousin is bringing up her children. Within a minute the table has split into two camps and the pudding has not even been served.

A debate night is the deliberate version of that: the same disagreement, but agreed in advance, properly chaired and finished in time for the cheeseboard. Done well, it becomes the hour everyone quotes on Boxing Day. Done badly, it is the reason two people are still not speaking in January. The difference is rarely the topic. It is the preparation.

Why the festive season is fertile ground for an argument

If you set out to design a setting for spirited disagreement, you would struggle to beat a British living room in late December. Everyone is in one place. Nobody can leave without explaining themselves. There is a captive audience of relatives who have been saving up opinions since August, and there is alcohol on the table.

The mistake is assuming the answer is to avoid difficult subjects altogether. Suppressed opinions surface sideways — through a remark about the washing-up, or a long story about someone's neighbour that is plainly about you.

A debate night works because it gives the tension a shape. You are not pretending the family agrees about everything. You are saying, out loud: we are going to disagree on purpose, for one hour, and then we are going to eat trifle.

Choose motions with somewhere to go

Most ruined Christmas arguments fail at the first hurdle: the topic. A good motion can be argued from either side by reasonable people, and it has no answer anyone can look up on a phone mid-sentence.

Motions that reliably work

• Is a buffet better than a sit-down dinner?
• Does Die Hard count as a Christmas film?
• Real tree or plastic tree — which is the better tradition?
• Should we still send Christmas cards?
• Is it ever acceptable to regift a present?
• Should a guest tell a host that the food disappointed them?
• You may invite three people from history to dinner. Who, and who does the washing-up?

Notice what these have in common. Low stakes, high opinion. Everyone has a view, nobody has evidence, and the argument is more entertaining than the answer.

Motions to leave for another year

Anything with a correct answer you already believe is not a debate, it is a lecture with an audience. Politics of any flavour, anyone's parenting, anyone's marriage, anyone's weight, anyone's salary and the question of who should have inherited the house all belong on that list.

One practical protection: ask quietly, a few days beforehand, whether anyone would rather a particular subject was left alone this year. One private message prevents most of the disasters.

Agree the ground rules before the first glass

Rules sound pompous. In practice they are what keep the evening from turning into a slow-motion ambush. Write them on the back of an envelope if you must, but say them aloud while everyone is still sober and still friendly.

• One speaker at a time. The chair decides who speaks next. Shouting "but that's ridiculous" from the sofa is not a contribution.
• Attack the argument, not the person. "That policy would be chaos" is allowed. "You're an idiot for believing that" is not.
• No phones. No fact-checking, no googling, no reading out a three-year-old headline. The debate is about opinion, not victory by search engine.
• Time limits are real. When the chair says stop, you stop. The pudding is not a rhetorical device.
• You do not have to mean it. Some of the best arguments are won by someone pretending to be passionately in favour of a terrible idea.
• The chair's decision is final. On time, on tone, on who speaks next, and on when the whole thing is over.

If that list feels heavy, remember that the alternative is not freedom. The alternative is Uncle Peter talking over the pudding for forty minutes while everyone else studies the pattern on the tablecloth.

How to run the hour

A good debate night has a shape: opening statements, a messy middle, closing arguments, and a hard stop. It should feel like a parlour game, not a tribunal. Here is a simple running order that fits between the main course and the cheeseboard.

1. Set the motion (2 minutes). Read it aloud. Check that everyone understands what is being argued.
2. Choose sides (2 minutes). Split into two teams, or let people volunteer. If numbers are uneven, the chair can assign one person to each side and let the rest heckle politely from the sofa.
3. Opening statements (5 minutes each side). One speaker per side. Two minutes each, maximum. No interruptions.
4. Open floor (15 minutes). Anyone can speak, but only if recognised by the chair. A wooden spoon makes an excellent gavel; a Christmas cracker crown makes an even better one.
5. Closing statements (3 minutes each side). The same opening speakers summarise, rebut, and land a joke if they can.
6. Vote (2 minutes). A show of hands, a secret ballot on the back of napkins, or a loud "aye" and "no". The result does not matter. The ceremony does.
7. Toast and pudding (immediately). The motion is now closed. Anyone still arguing has to do the washing-up.

The chair's secret job

The chair is not there to win. The chair is there to protect the game. That means keeping time, giving quiet people a turn, cutting off the person who has made the same point three times, and knowing when to say: "That's a good point, but we need to hear from someone who hasn't spoken."

A good chair also has a few phrases ready. "Let's park that for the pudding." "Can you put that as a question rather than a verdict?" "We're drifting from the motion." These are not just polite. They are the emergency exits that stop a debate from becoming a family reckoning.

How to land the plane

The most important part of debate night is the ending. If you stop at the wrong moment, the argument follows everyone into the kitchen and then into January. If you stop well, the disagreement stays inside the hour where it belongs.

Build in a clear full stop. When the vote is done, thank both sides. Say the motion is closed. Then do something physical: bring out the trifle, put on the Queen's speech, deal the cards, or suggest a walk. The change of activity matters more than the words. It tells the room, without anyone having to say it, that the fight was the entertainment and not the truth.

If someone tries to reopen the motion, use the house rule. "The debate is closed. You can have that argument next Christmas." Said with a smile, it usually works. Said with a plate of pudding, it works even better.

If it starts to go wrong

Even with a good motion and a firm chair, a debate can tilt. Watch for the signs: voices dropping, faces closing, someone repeating a sentence louder instead of better. That is the moment to intervene, not the moment to see who wins.

Have a pre-agreed safety phrase. It can be as silly as "sprouts" or as formal as "I think we've reached the pudding." Anyone can use it. When it is used, the chair immediately calls the debate to a close, no debate about whether to close it. The phrase is the fire alarm. You do not stand around asking whether there is really a fire.

It also helps to decide in advance what happens if two people clearly will not let something go. The chair can say, "That's a conversation for the two of you, not for the table," and move on. If the topic is genuinely raw — a recent bereavement, a divorce, a job loss — it should never have been a motion in the first place. A debate night is for the safe arguments: the ones where the worst outcome is that someone has to fetch more ice.

Afterwards: the Boxing Day dividend

The strange thing about a well-run debate night is that it makes the rest of Christmas dinner easier. Once you have argued about Die Hard on purpose, the accidental arguments lose some of their charge. You have proved that disagreement can be survived, even enjoyed, and that nobody has to storm out of the dining room to make a point.

You also get the best kind of family legend. Not the year Aunt Susan said the thing about the will, but the year Uncle Peter argued passionately that a buffet is morally superior, lost the vote, and then spent Boxing Day sending everyone articles about canapés. That is a story worth repeating. The other kind is not.

So keep the motions light, the rules short, the chair firm and the pudding close. Christmas dinner is already a high-wire act. There is no reason to make it a cage fight. But with a little preparation, you can turn the most predictable argument of the year into the hour everyone actually looks forward to.

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