If you dream that you have made a wager with someone it generally indicates that things will turn rather competitive in your life very soon. You might be pushed into making conclusions and actions hastily and this might not be always pleasant.
The meaning of a dream in which you wanted to make a wager but you could not due to some circumstance indicates that that you will be kept out of the competitive environment. You might want to enter into a competition but you will not be able to do so due to outside influence. Alternative meaning is that a small group of people would want to humiliate you in some way.
If you dream that you had made a wager and that you had won it means that you will emerge victorious from some sort of a competition in your professional life. Alternatively, this dream indicates that your luck will go up and that odds will turn in your favor eventually even if they were against you at the start.
If you dream that you had won a wager and as result you had won a lot of money or valuable items it means that someone is looking into your background and history. Your past actions might come to the forefront again and they might be judged again also.
The interpretation of a dream in which you refused making a wager due to not being confident that you will win it means that you should pay more attention to the loyalty of your friends. This is especially true for the friends that stem from your professional environment. If you are in a business partnership, you should re examine the terms of it.
If you in your dream you saw one of your friends winning a wager it means that the same friend will experience a very positive event soon.