Is it permissible to conduct a lottery in which participants pay a certain amount and each receives a gift whose value is greater than the amount paid, knowing that they do not know what they will receive?

Gambling is that which fluctuates between gain and loss, and it is forbidden and considered among the major sins. If the loss is absent, such that the matter revolves between safety and gain, or if everyone gains, then it is not gambling. As for a competition where a fee is required to participate, and the winner receives a prize, and the value of the prize is greater than the amount paid, with a person or another entity covering the difference, this is not permissible. This is because it involves selling an unknown item (gharar), and it resembles the forbidden transactions of mulamasah and munabadhah.