Gaming machines having normal and hot modes

A gaming system comprising:

• at least one processor;
• and
• at least one memory device storing a plurality of instructions which, when executed by the at least one processor, cause the at least one processor to:
• (a) cause an electronic gaming machine to operate in a default mode in which the electronic gaming machine has a default average expected payback percentage for each play of a wagering game;
• (b) determine when the at least one processor should determine if the electronic gaming machine should operate in a hot mode, the electronic gaming machine having a greater average expected payback percentage for each play of the wagering game in the hot mode;
• (c) when the at least one processor determines that the at least one processor should determine if the electronic gaming machine should operate in the hot mode, determine if the electronic gaming machine should operate in the hot mode;
• and
• (d) after the at least one processor determines that the electronic gaming machine should operate in the hot mode, cause the electronic gaming machine to operate in the hot mode for a designated period of play.