Unless the game theme or denomination is being changed, it's not normal to change the configuration. Normally, games are set once and that's it. Only those configurations that are approved by that jurisdictions regulations (tribal or state) are available for selection. The Slot Guru says:Modern slot machines 'are' computers with configurable software that allow operators (casino techs) to select one of many configurations. Yes, most slot machines have little computers that are 'editable' to change win rates and payouts.
