Georgia has a very, very clear public policy regarding wills - the courts want to uphold a will unless they're sure they shouldn't. This is because one of the basic concepts of property law is that a person should be able to decide what happens to his or her property when they die. There are some situations where, even though a person had a will, you can challenge it in probate court. Some of those include:

1. Invalidity - the will wasn't properly made due to a problem with the formalities of signing a will. 
2. Capacity - the person making the will didn't have the capacity to make or change a will. Georgia requires the person making a will - the testator - to have a certain mental capacity in order to make or change a will. However, that level is very, very low. If a person is basically aware of his or her family and property, they can make a will. 
3. Undue Influence - another person exercised undue influence over making the will. This is a common challenge - that someone, usually a new friend or caretaker of an elderly relative, convinced them to change the will for that person's benefit. The standard for this is that the third party essentially substituted their own wishes for those of the testator. Undue influence is a very technical objection, and is very case specific. It's also much harder to establish when the person exercising the influence is a family member of the testator. 

Obviously, the above list isn't a complete list. Additionally, there are other factors to consider in challenging a will, such as timing, whether a person has the right to challenge a will at all, and what the effect of successfully challenging the will would be. If you're not sure if you can or should challenge a will, call The Lilly Law Firm today at (678) 807-9150 to discuss the specifics of your case with an attorney.