1. A system comprising: a plurality of physical agents, the physical agents being configured for interaction with one another, each physical agent configured to: receive signals; perform actions in a physical environment in response to the received signals; and transmit signals indicative of the physical agent's state in the physical environment; at least one controller, configured to receive user input for controlling at least one of the physical agents, and further configured to transmit signals for controlling at least one of the physical agents; and a host device, configured to: receive signals indicative of the physical state of the physical agents; transmit signals specifying actions to be taken by the physical agents; store virtual representations of the physical agents, the virtual representations of the physical agents being configured for interaction with one another; and maintain substantial parity between the physical states of the physical agents and the states of the corresponding stored virtual representations of the physical agents; wherein maintaining substantial parity between the physical states of the physical agents and the states of the corresponding stored virtual representations of the physical agents comprises: determining whether there is disparity between the physical states of the physical agents and the states of the corresponding stored virtual representations of the physical agents; and responsive to a disparity, automatically reducing the disparity by performing at least one selected from the group consisting of: transmitting a signal to at least one physical agent to change the physical state of the at least one physical agent to reduce the disparity; and modifying at least one stored virtual representation of a physical agent to reduce the disparity.