A computer-implemented method enables participation by a plurality of clients in a first multi-dimensional virtual environment and a second multi-dimensional virtual environment. A first client sets an object in the multi-dimensional virtual environment system to function as a portal to a second multi-dimensional virtual environment. The portal can be used by the first client and/or the second client to enter the second multi-dimensional virtual environment. A server system receives from the first client data indicating that a first object in the first multi-dimensional virtual environment has been set to function as a portal to the second multi-dimensional virtual environment, and receives from a second client participating in the first multi-dimensional virtual environment data indicating that the second client has invoked the first object. The server system transmits to the second client data representing objects in the second multi-dimensional virtual environment.