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Place the Builder where the structure is to be built, then place a written Blueprint or Template in the Builder slot. If a Blueprint is used, the Builder requires the exact type of ingredients to build the structure. If a Template is used, the Builder will use any ingredients to build the structure. The Builder will clear all blocks from the space before building the structure.
To have the Builder build multiple copies of an item, say a path or a bunch of fountains in a row, use Path Markers before placing the Builder. Place Path Markers down and right-click them to activate them. They will connect to the nearest Path Marker and specify a red line by which the Builder will follow. This line can be diagonal and does not have to be on the same level as others. Then place the Builder next to the first Path Marker and power it.