Betting bilaterally and doing similar things are regarded as gambling. For instance, before two people races if one of them says, “If you outrun me, I will give you such and such amount of money; if I outrun you, you will give me such and such amount of money”, such a bet is regarded as gambling.
However, if the bet is unilateral, it is permissible. That is, if one of them says,” If you outrun me, I will give you such and such amount of money but if I outrun you, do not give me anything”, such a bet is legitimate. The person who obtains such money can use it.
It is not permissible to arrange a match or a game by laying some conditions and to take the prize given as a result of the match or game. Such a practice is regarded as gambling.