You have spent £2 on a lottery ticket. On Saturday evening you may be a millionaire. Or, more likely, not.
But meantime, the auditors arrive. They must confirm that your accounts show a true and fair view. An old-fashioned auditor might allow you to record the lottery ticket at its historic cost of £2. A modern one would want to assess its fair value.
But there is no market in second-hand lottery tickets. The auditor might allow you to treat it as a “level two” asset which can be valued by reference to the price of other traded items and use a discount to the primary market price. Or the accountant might encourage you to “mark to model”: multiply the payouts by their probabilities and compute an expected value, £1.20 say, though good models attach different values to different tickets because some numbers are more popular than others.