Scratched onto a flat part of the base of one of the extraordinary Assyrian winged bulls are a couple of dozen squares. They’re the board for a dice game and were incised around 710BC (although earlier examples of the game have been found dating back 4500 years). The thing seems to have been a sort of “race” game with counters (think of Ludo).
You can keep your hoards of gold and silver, your Egyptian mummies, your blockbuster Viking exhibitions. For me, the most wonderful piece in the whole British Museum is a bit of graffiti, not done by any artist or craftsman, but by a bored squaddie looking for ways to kill time.