You can learn a lot about your opponents' hand by using the power of observation, & you can use this knowledge to strategically decide which cards to keep and discard. Iage of gods slotsn Rummy, using the power of observation entails assessing your hand frequently, observing the moves of other players, and selecting which cards to keep and discard logically. You can't succeed in the game of Rummy unless you can adjust to the various variations. Rummy comes in a lot of different forms, each with its own rules & goals.