An artificial universe is defined that has entirely deterministic laws with exclusively local interactions, and that exhibits the fundamental quantum uncertainty phenomenon: superposed states mutually interfere, but only to the extent that no observation distinguishes among them. Showing how such a universe could be elucidates interpretational issues of actual quantum mechanics. The artificial universe is a much-simplified version of Everett's real-world model (the so-called multiple-worlds formulation). In the artificial world, as in Everett's model, the tradeoff between interference and observation is deducible from the universe formalism. Artificial world examples analogous to the quantum double-slit experiment and the EPR experiment are presented.