What are the reasons a will can be challenged?
You can generally challenge a will for any reason which would, if you were successful in proving your claim, cause the will to be invalidated (or at least cause some portion of the will to be found invalid). Thus, you can challenge a will by arguing that one of the basic will requirements was not met when the will was initially created. This, in fact, is the most typical reason wills are challenged. The other typical reasons wills are challenged include claims that the deceased created the will while suffering from delusions, while under undue influence or duress, or because of some fraud or mistake.