Minecraft wiki entry for Logic, associated text: An OR gate () is a gate which uses two or more inputs and whenever any input is "on", the output is also "on". The only time the output is "off" is when all inputs are "off". Note that since the OR operation is associative and commutative, OR gates can be combined freely: The player can compare huge numbers of inputs by using small OR gates to collect groups of inputs, then comparing their results with more OR gates. The result will not depend on the arrangement of the inputs, or on which ones were combined first.