Lucky Candy is a booster in Candy Crush Saga that debuts in level 131. (On Mobile, it is given immediately after completion of level 130). It releases candies that can help meet the objective(s) of a level. For example, a striped candy is produced in levels requiring striped Candy and/or combos, a wrapped candy in levels requiring wrapped candy and/or combos, or a colour bomb in levels requiring colour bomb and/or combo, and normal colour candies in levels requiring certain amount of coloured candies. It is only used in candy order levels. It looks like a pink ball with a check-mark.
They appear to be metallic versions of normal candies.
These candies will only give candies related to the orders. If the order tells you to gather certain colours, they are mostly useless because they only transform into one of those coloured candies. If the order tells you to combine special candies or detonate them, it will give a special candy involved in detonation or combination, and is more useful.
If a lucky candy is going to produce a striped candy or wrapped candy, the colour of the outcome will be random.
This booster is winnable on the daily booster wheel, but it is incredibly rare to win (however, not as rare as the Jackpot).
If part of the order has been fulfilled, they will only produce candies for the rest of order. For example, in level 236, if you have collected all striped candies and wrapped candies first, further lucky candies will only produce colour bombs.