This speculation fermented by a discussion about a young man doing his GCSEs, and good luck to him. Well, at the time he was finishing GCSEs, so there was not much point wishing him good luck really. Or was there?
Think about it. ‘Luck’ is not ‘work hard’ or ‘be clever’ or anything like that. It is not ‘I have bribed the examiner’ or ‘I have stolen the paper in advance, here it is’. It is not in fact anything tangible. When you wish someone ‘luck’ you are not saying “The following acts will have a causal impact on the outcome of the events we are discussing.” In part you are not saying that because normal people surprisingly rarely talk like that, but mainly because the whole point of ‘luck’ is that it is something over which you have no influence. It is acausal, and as such not limited by such tedious things as the speed of light or the laws of thermodynamics. In principle, then, I could wish the examinee ‘good luck’ at any time in his exams, and the wishing would be just as effective. Indeed, I could wish him luck well after the exams have finished. So I wished him good luck.
But we can go further. Why limit oneself to after they have finished? I could wish my grandchildren luck in their exams, even though I have no grandchildren and by the time they are 16 exams will have been replaced by something incomprehensible and internetty. Even better, one could wish for good luck not just after alea jacta est, but after alea had landed and everyone had seen you threw a double one and ended up sliding down a snake. One could go up to car crash victims and say “Good luck!” and, if luck works at all, they should retrospectively have better luck and therefore not be in the crash in the first place. I encourage you to try this. I am confident that the difference in injury level between you and the car crash victim will be substantially reduced as a result.
Of course, one has to be careful about this. The car crash you carelessly prevented by wishing the driver good luck might have kept a homicidal maniac off the streets, which would be very bad luck for someone. Maybe the reason that saying “Good Luck!” does not obviously work is luck conflict. Nearly every member of the human race wishes ‘good luck’, and so, on the ‘what everyone believes must be right’ thesis that underlies so much of theology, luck must exist and be a powerful force indeed. But it does not very often have a dramatic effect, because people throughout space and time, including in our far past and future, have carelessly wished for things that are lucky for them but unlucky for us.
So we can solve this problem. We have the technology! All we need to do is set up a Good Luck clearing house on the internet, with microphones in every street corner scanning for the words “Good luck!” in the local language. A complex algorithm will then match the various luck-wishes with each other and the probably outcome, and people would be fined for careless Luck-wishing.
The technology is readily extendable to other areas of human belief. Take prayer, for example. Francis Galton famously did a statistical study on the efficacy of prayer, and concluded that the large number of prayers said for the health of the royal family (and for the local minister, local worthies and so on) had no effect on their health. But of course not! Galton was studying historical records from 1758 – 1843 , during which time England (in its various forms) fought 43 wars against France, the Austrian Empire, the Ottoman Empire, Russia, almost all the states that ended up being Germany and Italy, Holland, Sweden, Afghanistan (plus ca change…), various bits of India, a couple of states in Africa, and the Chinese Empire. Oh, and the American colonies (lost those). At any one time at least three entire countries were praying for Britain and all its leaders to drop dead. It is amazing, really, that any member of the British Royal Family made it past their tenth birthday. Obviously without global collaboration, prayer will not work.
And so – ePray. a social networking business with a difference, coordinating wishes and prayers through trading, global surveillance and suitable financial incentives. A boon to society, and final and conclusive proof of the benefit of “Good Luck!”
Ah, but we can go even further! Why should the effect of wishes and prayers be confined to Earth? Acausal, faster than light, the prayers of the Zxigoopids of Gortle should be able to affect Earth as well as Gorlte, and visa versa. So we could pray, desire and fervently wish that stars across the sky should go nova, just for the pretty lights they make. The ones that did not blow up, annihilating any planets around them, would be thus be proven to harbour intelligent life whose counter-wishes – to wake up in the morning at a temperature below the boiling point of carbon – would have neutralised ours.
With good luck, we can look forward to the ePray-SETI collaboration proving the universe to be full of intelligent life.
 Exams taken in England and Wales at 16 years of age, typically in 8 – 10 subjects for bright young people, including a ‘core’ of Maths, English, Sciences and so on, and the a selection from a wide range of other subjects.