<p>A system for wagering during a wagering period having a wagering base with a first plurality of pools each with an outcome accessed by an input wager. A plurality of terminals is provided at which wagers are input, each directed to access an outcome in one of the pools. A processing system is configured to process the input wagers in a manner whereby each input wager either: a) accesses; or b) fails to access an outcome. The processing system is further configured so that there is an initial pre-assigned probability of accessing the outcome of each pool through an input wager. The processing system is further configured to identify a collective return by determining the number of input wagers that have accessed an outcome in a particular pool. The processing system is further configured to change the wagering base after the wagering period has begun and before the wagering period is concluded based upon one or more system operating parameters detected during the wagering period.</p>
