In this paper, we propose rapid-control prototyping (RCP) for a robot soccer using the SIMTool that has been developed in Seoul National University, Korea, for the control-aided control system design (CACSD). The proposed RCP enables us to carry out the rapid design and the verification of controls for two-wheeled mobile robots (TWMRs), players in the robot soccer, without writing C codes directly and requiring a special H/W. On the basis of the proposed RCP, a blockset for the robot soccer is developed for easy design of a variety of mathematical and logical algorithms. All blocks in the blockset are made up of basic blocks offered by the SIMTool. Applied algorithms for specific purposes can be easily and efficiently constructed with just a combination of the blocks in the blockset. As one of the algorithms implemented with the developed blockset, a novel navigation algorithm, called a reactive navigation algorithm using the direction and the avoidance vectors based scheme (RNDAVS), is proposed. It is shown through simulations and experiments that the RNDAVS designed with the proposed RCP can avoid a local minima and the goal non-reachable with obstacles nearby (GNRON) arising from the existing methods. Furthermore, in order to validate the proposed RCP in a real game, we employ an official simulation game for the robot soccer, the SimuroSot. Block diagrams are constructed for strategy, path calculation, and the interface to the SIMTool. We show that the algorithms implemented with the proposed RCP work well in the simulation game.