When a stag sees that his doe is being taken from him by another stag, they challenge each other and buck horns in a very raw and primal fashion. They beat each other up until there is one sure victor and the true victor takes home the prize, which is his female companion. The deer are not just being aggressive but assertive. If your dominance comes into question you may find yourself in the same situation.
Though this dominance is usually sexual in nature it does not have to be. Many times the lead male in a deer pack will be challenged by a younger male. Generally the leader of the pack is the one with the largest antlers. The reason that they are challenged does not have to be over a female deer but can even be over simple issues such as providing food and caring for sick and injured deer. You would be surprised how complex these groups of deer are, and how humanlike many of their qualities are.
This same thing can happen and does in many occasions in human society, usually at work. Many times a new employee will be inducted into the office team only to try to outshine his peers by doing all of their work for them, and taking on more responsibilities than he has to just to impress his superiors. This might require him to infringe on your territory, trying to do your job for you. You do not want this to happen so your natural instinct would be to show your antlers so to speak, and fight back against him. This may not resort to a physical fight but it is essentially the same idea.
Also, the competition for a specific romantic partner is a fairly common one in life. When you notice that your wife or girlfriend (or husband or boyfriend for that matter) is being hit on by a member of their opposite sex, then it is your natural instinct to move into protective mode and try to seek the ruin of the one that is trying to get your significant other’s attention. It is a primitive and territorial instinct, but one that is necessary in order to preserve the integrity of a relationship. Besides, seeing someone defend their claim over you can be very sexy.
If any of these situations are going on in your life currently it is usually a good explanation for why you might be dreaming of antlers at the moment. These moments of romantic and competitive tension are what the sets of antlers that you see in your sleep are all about. The antlers represent raw sexuality and are a sign that you need to assert yourself more as well as being a sign that you should claim the place in your societal hierarchy that you feel you deserve. Don’t let anyone rob you of what you deserve.