Abstract: A fantasy simulation allows participants to challenge each other by comparing the performance of one participant's reality-based selection to another participant's reality-based selection. The simulation also allows participants to wager a limited or unlimited amount of simulated funds on the outcome of the challenge. Participants challenge other, individual participants or groups of participants while the simulation measures a reality-based metric associated with all challenge participants' reality-based selection over a period of time. At the conclusion of the period of time, a challenge winner is determined from the change of the metric.