The Mighty Cash Feature is triggered by landing 5 or 6 or more Mighty Cash Bonus Symbols, each of which have credit awards on them: you only need 5 for the nickel or dime denomination. In addition, higher levels increase your chances for winning Jackpot Progressives and Mini & Minor Bonuses. First though, you choose your Mighty Cash level from Blue for 8 credits to Yellow for 24 credits and the higher your level, more valuable Mighty Cash symbols may land. In Outback Bucks, you win in the base game by landing 2 or 3 of the same symbol on adjacent reels from left to right, depending on the symbol, and starting with the leftmost reel although the real fun is with one of the two special features of the game.
Mighty Cash continues to dominate casino floors and truth be told it's hard to keep track of all of the versions and features.