The Imperial Slot Machine provides battle-weary warriors a respite from worldly ennuis and a chance to win exciting prizes for free just for logging on every day---or even more prizes for a small fee from purchasing (or winning) Imperial Coin sets.
The Imperial Slot Machine takes one free daily play or Imperial Coins in sets of 1, 5, or 10, spitting out an corresponding number of prizes from Treasures like Building Books to Consumables like Experience Crystals and even the occasional Purple Hero! Every Slot Machine of the four has one Purple Hero in its stack of 500 or 1000 prizes; once the Purple Hero is drawn (and it can be drawn at any time---even on the first pull as one of the testers discovered during a pre-release run of the Dante's Circle expansion pack in which the Imperial Slot Machine function was released), the stack resets to its original number of prizes, and another Purple Hero is thrown into the mix.
The Imperial Slot Machine is a great way to get free Items---particularly Building Books and Research Manuals---that might not otherwise be obtainable other than in the Mall. It is one of several ways in which the Imperial Warfare: Dante's Circle expansion pack tries to appeal not only to paying players but also those who make few or no purchases to improve their characters.