Is a paid lucky draw permissible if every participant is guaranteed a prize worth more than the fee paid?

Summary

A paid lucky draw where participants may gain or lose, by receiving a prize worth more or less than the fee or nothing at all, is gambling and is forbidden. If every participant is certain to receive a prize worth more than the fee, it is not gambling because there is no chance of loss. It is still forbidden, as it is in substance a sale containing gharar (uncertainty), since the prize being bought is unknown until the draw. The fatwa likens it to the sale by throwing a stone (bai' al-hasa).

Written in our own words from the original fatwa — check the source before acting on it.