Category B gaming machine
One of the classes into which British law sorts gaming machines by maximum stake and prize. Category B covers the higher-stake machines found in casinos, betting shops, bingo halls and adult gaming centres.
In practice
The category has sub-classes (B1, B2, B3, B3A and B4), each with its own stake and prize limits and its own list of premises where the machines may be placed. A rule change for "Category B machines" therefore reaches casinos, betting shops, bingo halls and arcades at once.