Abstract: Methods, systems, and media for well planning are provided. The method includes displaying a three-dimensional representation of a subterranean domain, and receiving a selection of a location in the representation of the subterranean domain. The method also includes identifying an object of a well plan associated with the location, and receiving an instruction to modify the object. The method further includes editing data associated with the object based on the instruction, and visibly modifying the object in the representation of the subterranean domain, substantially in real-time with respect to receiving the instruction. The method also includes determining, using a processor, that the editing of the data results in at least a portion of the well plan being outside of a constraint, and changing a display of the object to indicate that the editing results in the at least a portion of the well plan being outside of the constraint.