How is game of skill different from game of chance?

Stock markets certainly come under the game of skill category where people with experience have a better chance of making money than the rookies. A debate around game of skill and game of chance has been raging for a while now.
Before taking a call on the taxation of online gaming and betting, the group of ministers looking into the matter should first come out with a clear definition to clear the confusion and reduce scope of more litigations, a law panel of the GST council has said. This podcast tells more.