Have you heard of the game 2048? It is addictive.
You can also make your own version of the game – I made an Alphabet one. And then I thought of the possible royal twists – The longest reigning British monarchs for example. Or this Royal Heirs edition, and the complementary Monarchs, going from shortest “reign” to longest.
(I was originally going to make it all European, but there is one monarchy short in Europe for that, so I included Thailand. Since Alois hasn’t taken completely over in Liechtenstein, I still have him down as a heir.)