Progressive jackpot slots have been the highlight of the online gaming industry. In progressive jackpot slots a part of each wager is kept aside. This keeps on accumulating till a predefined event takes place. Then the entire amount, known as the jackpot, is given to the player in whose wagering the event takes place.

In the traditional progressive jackpot slots this event is defined within the game. One of the symbols on the reels is designated as the wild symbol. This symbol usually is central to the theme of the slot game. When five wild symbols align in the highest pay line the jackpot is hit. In order for the progressive jackpot to be won the player has to bet the maximum amount. This means that he must wager the maximum possible coins of the highest denomination and cover all pay lines. Usually the first four reels stop first. Imagine the excitement of the player when he sees four wild symbols in the highest pay line. The fifth reel is still spinning. The suspense over whether the jackpot will be hit is almost unbearable.

Online slots are the most innovative of all casino games. Software developers evolved a mechanism that would bring an even greater surprise to the winner of the progressive jackpot. No event within the game was defined as being necessary to hit the jackpot. Instead the software was constructed in such a manner that the jackpot was hit randomly. A random number was generated within the software and if that number corresponded to the specified requirements for a progressive jackpot then the hit was announced on the screen. Otherwise no indication appeared on the screen. Therefore the progressive jackpot was not accompanied by any specified combination of symbols on the reels. The jackpot could be hit even if there was no line or scatter payout. This increased the element of surprise. Now there was no advance warning of four symbols aligning in the first four reels. The progressive jackpot hit was announced just out of the blue. This mechanism of getting the progressive jackpot is known as a random jackpot.

There was another major advantage of the random jackpot. In the traditional method the player had to wager the maximum bet in order to be eligible for the progressive jackpot. Often due to the high level of the maximum bet the progressive jackpot was out of the reach of many low rollers. Thus a large section of wagerers was out of contention for the progressive jackpot. The random jackpot addressed this issue. Not only could it be won on any combination in the reels but also it could be won on any amount wagered. Hence in the random jackpots even low rollers had a chance of winning. However, software developers have thought it fit to give the high rollers a greater chance of winning. Therefore the software has been so constructed that the probability of hitting the jackpot increases with the amount wagered. The probability is highest when the player has wagered the maximum bet. In this manner random jackpots cover the interests of both low rollers and highly rollers.

There are several examples of popular random jackpots. The branded Marvel Hero series of online slots, developed by Cryptologic, fall in this category. The latest Real series slots from Real Time Gaming also have random progressive jackpots. However the most famous random progressive jackpot is in the Mega Moolah online slot from Microgaming. It operates in a slightly different manner. The jackpot is not triggered directly. What is triggered is a spin the wheel type bonus round. In this bonus round players are guaranteed to win one of four jackpots, the highest of which is the full amount progressive jackpot. Last week Mega Moolah has paid out over $6 million to one lucky player.