First, work out how much of it is luck

Ask three questions before you write a word. Could this person have prepared any harder than they have? Is the decision actually theirs, or does it sit with a panel, an examiner, a surgeon, or a stranger reading applications at four in the afternoon? And will the card land before the thing, or after it? The answers pick the register. Preparation-heavy events want the work named and the luck kept light. Chance-heavy ones can take all the luck language you have. Events that sit outside the person's control want neither luck nor odds. They want company.

Here is the difference on one ordinary situation: a second attempt at a driving test. The overshot version wishes for luck and names none of the work:

"Good luck on Friday! Fingers crossed your examiner is kind and the manoeuvres are easy ones and nothing weird happens on the dual carriageway!"

It means well, and it still lands wrong, because every clause hands the outcome to somebody else: the examiner's mood, the route, the traffic. The same card, calibrated:

"You have done the hours, including the hill start on the road you hate, in the rain, twice. Friday is just the part where somebody watches."

The third question, timing, catches more cards than the other two. A good luck card is a bet placed before the event; the same words arriving afterwards read as a verdict on it. If you know the card will land late, do not post the before-version and hope. Change the first line to acknowledge the wait or the result, and keep the rest. People can tell when a card was written for a Thursday that has already happened, and the kindest reading they can give it is that you were busy.

If the thing on Thursday is one of the standard situations, wording banks already exist for exam cards and interview cards, sorted by exactly that situation. What follows here is everything around the banks: the calibration itself, the registers a situation bank cannot cover, and the cases where the occasion is not the problem and the wording is.

For the person who has done the work

When someone has revised, trained, rehearsed or practised their way to the day, luck is the smallest part of what is happening, and the card should say so. Name the preparation in the specific form you witnessed it: the flashcards, the early runs, the practice answers given to an empty room. These lines keep the luck word in its place, which is mostly out of the sentence.

  • Four months of flashcards on the fridge door have to count for something. Go and collect.
  • You have explained your own CV to the bathroom mirror more times than either of us can count. The panel is getting the rehearsed version, and the rehearsed version is good.
  • Hill starts on the steep road, in the rain, with a passenger who kept going quiet at the wrong moments. You have already done the hard version of this test.
  • Twelve weeks of training runs in weather nobody would choose on purpose. Race day is the lap of honour.
  • You know this presentation better than the people who commissioned it do. Thursday is a formality, and I hear there are biscuits.
  • Every scale, every etude, every neighbour pretending not to hear through the wall. The exam is ten minutes of what you have already done a thousand times.
  • The thesis is printed, the slides are done, and you have survived the hostile practice question twice. All that is left is the room.
  • You revised through two colds and a boiler breakdown. Whatever is on that paper, you are not the risk factor in this arrangement.

When luck honestly is most of what is left

Some events really are a lottery once the preparation ends: auditions with two hundred applicants, offers on houses, shortlists, draws. Pretending otherwise sounds false, and the person knows it. This is where luck language earns its keep, said plainly and without dressing it up as fate.

  • Everything you could control is controlled. For the rest of it: luck, weather and a following wind, all formally requested.
  • Two hundred people want the same part. Yours is the audition I will be thinking about at eleven on Tuesday.
  • The house, the chain, the other buyers: none of that is in your hands now. I hope the phone rings with the right voice on it.
  • May your name come out of whatever hat they are using, and may it come out early, while you are still in the room to hear it.
  • For the shortlist, and for the person reading applications late on a Friday: may yours be the one they read while they are still being generous.
  • The forecast says rain and the course says hills. Luck for both. You have earned a tailwind somewhere in there.
  • Part of this is yours and part of it is the world's. The world's half has been written to, in strong terms.

Performers have their own word for it

Theatre people are the exception to this whole article: backstage, 'good luck' is treated as a jinx and avoided on purpose. Actors say 'break a leg' instead, a phrase documented in American theatre from the 1930s and possibly borrowed from the German 'Hals- und Beinbruch'. Dancers use a different word again, 'merde', because the legs are the equipment. Getting the tradition right is the whole card. Getting it wrong in good faith is usually forgiven and always remembered.

I learned this by posting a card to a friend, Eileen, before a dance show at the Edinburgh Fringe in 2019. I wrote 'Break a leg tonight!' across the middle of it in my best handwriting and sent it with flowers to the venue. Her reply, afterwards, in full: 'Dancers say merde. The legs are the equipment.' She was kind about it. She has also never let it drop.

  • Break a leg tonight, and take the bow you have been rehearsing in your kitchen.
  • Merde, for every turn that behaved in rehearsal and for the two that did not.
  • Toi toi toi, and may the props table hold everything it held last night.
  • For opening night: a full house, warm lights, and one laugh in the second row that starts all the others.
  • You have sung it in the car a hundred times. Tonight there is furniture and an audience. It is the same song.
  • The only review already written is this one, and it is five stars. Go and collect the rest.

When the outcome is not theirs to control

Before an operation, during a wait for results, while a board or a panel decides: these are the cards where both pep and luck misfire. Nobody in a hospital gown needs to be told they have got this, and the odds are a subject for other people. What a card can do here is keep company and make one or two plain promises.

  • Thursday, ten o'clock: consider yourself thought about, at length and on purpose. The kettle offer stands for whenever you are home.
  • You do not have to be brave in this card's company. It is not going anywhere, and neither am I.
  • Whatever the letter says when it arrives, the plan from this side is unchanged: I will drive, I will cook, I will sit in the corridor.
  • For the wait, which is the worst part: may it be shorter than they quoted you, and may the tea trolley find you twice.
  • This one is not yours to pass or fail. You are the person it is happening to, and being looked after is the whole of your job in it.
  • Thinking of you at nine, when it starts, and at eleven, when somebody kind will be telling you it is done.
  • No pep talk in this card. Just a promise that your phone will have one message on it when you switch it back on, and it will be this, again.

One more recipient nobody writes to: the person doing the waiting alongside. The partner in the corridor, the parent in the car park, the friend refreshing a phone for news that is not theirs to be given. They get no card because the event is not happening to them, and they are usually holding the coats, the keys and the timetable for the person it is happening to. A short line to them, the same week, costs almost nothing and is remembered out of all proportion: you know where the waiting room is, and you said so.

Group cards, where three people write the same line

The known failure of the shared good luck card is duplication: five signers, five versions of 'you have got this', and the card reads like a form letter the person filled in about themselves. The fix is unglamorous. Somebody goes first with the specific line, and everyone after writes a different angle: the practical offer, the joke, the short one. If you are organising, say so on the invite. People are relieved to be given a lane.

  • From the desk nearest the window: yours is the first presentation deck I have ever read to the end voluntarily.
  • The night-shift contingent has voted, and we are all expecting the good version of Friday.
  • I have heard the practice runs through the partition wall for a fortnight. The panel has no idea what is coming.
  • One line each was the rule, so here is mine: bring back a story, and an implausible one if you can manage it.
  • Everyone's name is on this card, but the biscuits in the kitchen on Monday are from me specifically.
  • Signing for the whole group chat: we have collectively decided you are the favourite. Do not make us look foolish.

When you do not actually know what the thing is

A colleague's big Thursday. A nephew's finals of the thing. A friend who has gone quiet and purposeful about a date they will not explain. Invented specifics are worse than none; a guessed detail that misses makes the card about your guessing. Honest vagueness, written warmly, is a real register, and people recognise it as respect.

  • I do not fully understand what Thursday involves, and I am not going to pretend otherwise in a card. I do know you have been working at it for months. Go well.
  • For the thing with the panel, the portfolio and the part you are not allowed to talk about: fingers crossed for all of it, from here.
  • Whatever the next stage of the process is called, I hope you get the email about the one after it.
  • You have been mentioning this date in the tone of voice people use for weather warnings. It is marked in my calendar too, now.
  • Details unclear, support unlimited. Report back when you are allowed to.
  • I asked no follow-up questions in the corridor, but I have thought about it since. Hoping for the full celebration version on Friday.

The vague card does carry one obligation: the follow-up. A card that says 'details unclear, support unlimited' buys you the right, and the duty, to ask afterwards what the thing actually was. Asked the week after, the question reads as care. Never asked at all, the card curdles slightly, and the person files you under people who performed an interest. Write the vague card by all means. Then make the call.

Short ones, for a card that arrives with something else

When the card is riding with flowers, a plant, a book or a bottle, its job shrinks to a line or two and the gift does the carrying. Short is not the same as generic, though. One date, one detail, one true thing still fits on a gift tag.

  • Thursday. The hard part is already done, and you did it.
  • Luck, in the small places where it is actually needed.
  • Go and be the story we hear about on Friday.
  • Prepared beats lucky. You are both, in that order.
  • Breakfast, then the thing, then the story. See you at the story.
  • One sleep, one morning, done. Thinking of you through all three.
  • The good version of this week, please. Requested in writing.

Lines to leave out of a good luck card

"Good luck! You will need it."

"Fingers crossed nothing goes wrong."

"Break a leg!" (sent to a dancer, or to anyone whose leg is the actual problem)

"May the odds be ever in your favour."

"Don't mess it up!"

Each fails in a different direction. The first says the quiet doubt out loud. The second names the disaster it claims not to be thinking about. The fourth borrows a film line about children fighting to the death. The last one is an instruction wearing a joke's coat. If a line sounds different read in a worried voice at midnight than it did at noon, it is not a good luck line, whatever it claims to be.

The borrowed statistic belongs in the same bin: the passing rate, the acceptance rate, the percentage of people who get through on the second attempt, quoted at somebody as if it were a blanket. Numbers about other people's Thursdays do not warm anybody's. If the kindest true sentence you can find about the odds is a statistic, write the sentence about the person instead. There is always one.

Turn it into a group card

Of all the cards that circulate for signatures, this is the one with a deadline it did not choose: the event sets it. A paper card that reaches its last signer on Friday afternoon is a congratulations card whether it wants to be or not. A group card everyone signs online keeps the deadline honest: set the signing cut-off a day early, chase the two people who always need chasing, and the card lands while it is still a good luck card. You can create a card online in a couple of minutes.

If the event turns out to be the end of a course, the graduation card guide picks up where this one stops, because by then the register has changed: the luck has either happened or it has not, and the card's job is to mark the thing rather than wish for it.

The card I sent Eileen in 2019 is still in the side pocket of the bag she teaches from, seven years and one career change later, its corner gone soft where it gets handled. Every September a new student asks what merde means, and she reads my wrong phrase out loud as the start of the explanation. It is a longer life than most cards get, and not the one I was aiming for.