Or put multiple ScratchCard stacks inside SortStack, so one is picked and loaded at random:
Of course, that will not stop a user hitting the refresh button in their browser, until they get the answer they want!
If you want to prevent that happening, then you will need to take a personal identifier from the user - like their IP address or email address - store that in a database and then loop it through if / else statements to terminate the randomiser, if those details are found to already exist. But as you can read, it starts getting very complicated and risky from a GDPR compliance perspective.
The only other option I can think of would be to buy my AdvancedPublisher stack and perhaps configure it to display the ‘winning’ ScratchCard stack at a particular time of day or week:
I know quite a lot of people are using AdvancedPublisher right now, to do ‘daily deals’ on their websites, during the countdown to Christmas. The stack works terrifically well for this purpose.