Fortress or castle, with elements appropriately arranged to ensure successive lines of defence in order to maximize the protection of what is most valued. Importance is attached to the strategic location and the relationship to the surrounding terrain. Battle plan, whereby opposing generals locate the different functional units of their respective forces both in relation to one another and to the opposing force, in order to favour respective strategies. Special attention is given to terrain, logistics and the training and morale of participants. Ritual, dramatic or dance movements, in which participants continually modify their relationship to each other, possibly to bring about a sequence of changes in the overall pattern they constitute.
Some forms are completely pre-determined, others are partially or completely improvised.
In some forms all participate all the time, in others they may be absent for the part of the sequence in which their role is most stressed, or when it is stressed by their absence. The orientation of the configuration as a whole is vital to its operation, as in the case of the microwave receiver or the radio-telescope. It is only through the use of magnetic forces that the plasma may be kept from destroying any material container. Reactor, in which particular attention is given to the configuration of heating, cooling, agitating, input and output elements, in order that an optimum transformation of materials should take place. This applies as much to the simple crucible, although the precision and symmetry of the configuration is most evident in nuclear reactor design.