Two wills. Reciprocal. Will only covers property in sole name of decedent not joint/survivorship or with designated beneficiary like insurance policy or IRA. I am handling a $4 Million plus estate now with all assets joint, even the 3 cars, hence no formal probate proceedings necessary. In CT, still have to clear title to real estate when joint owner dies. I'm sure its the same in your jurisdiction. Amazing that we still read cases about people buying real estate without a title search and getting "surprises". Out west, there are also retained mineral and oil rights to watch out for.