VEXcode 123 has puzzle-piece shaped blocks that connect above or below each other and are used to code. A series of connected blocks is called a stack. There are five different shapes of blocks and each shape tells you about its role in the project.
|Block Shape||Description||Block Examples|
|Hat blocks||Start a stack of blocks and are shaped to attach blocks below them.|
|Stack blocks||Perform main commands. They are shaped to attach above or below other stack blocks.|
|Boolean blocks||Return a condition as either true or false and fit inside any blocks with hexagonal (six-sided) inputs for other blocks.|
|Reporter blocks||Report values in the form of numbers and fit inside any blocks with oval inputs for other blocks.|
|C blocks||Loop the block(s) within them or check if a condition is true or false. They are shaped to attach stack blocks above, below, or inside them.|