Minecraft wiki entry for Randomizers, associated text: Randomizers are redstone circuits which generate random signals. They can be used in a multitude of things, from running a light show, to making a casino. Note that randomizers, like the majority of redstone circuits, will only work in active chunks. If this is wanted for a adventure map or something where the player may get far away, it may be desirable to build the randomizer in spawn chunks‌[Java Edition only] or a ticking area.‌[Bedrock Edition only]