Rum-running is like playing a game of "secret agents" where people would try to sneak alcohol across the borders of countries that had laws against it.
You see, a long time ago, some countries decided that drinking alcohol was bad and made it illegal. This meant that nobody was allowed to make, sell or drink alcohol. But some people really liked to drink alcohol, and so they found ways to sneak it in from other places where it was legal.
These sneaky people who transported alcohol were called rum-runners. They would hide the alcohol bottles in secret places in their cars, boats or planes and try to cross over the border without getting caught. They would also use secret codes and signals to communicate with other rum-runners so that they could pass the illegal "booze" (as they called it) from one person to another.
But being a rum-runner wasn't easy. They had to be very good at hiding the alcohol, avoiding the police and navigating through difficult terrain like oceans or mountains. Sometimes, their plans would fail, and they would either get caught or have their alcohol confiscated.
In the end, the laws against alcohol were eventually repealed, which meant that people could drink legally again, and rum-running became a thing of the past. However, the stories of these daring smugglers live on as thrilling tales of adventure and danger.