Wills can be contested on the grounds of undue execution, will had been revoked, the testator lacked testamentary capacity at the time of creation, or the testator was fraudulently induced to create the will, or undue influence was exerted upon the testator. Will contests are fairly common and can be costly and time-consuming to litigate. The person who challenges a will must have legal standing. This usually occurs when, for example, children are to receive disproportionate shares under the will, or when distribution schemes have changed from a prior will. Also, will contests often arise from disputes over who was designated as the executor.