In 1983, Gladys Moore (plaintiff) entered into negotiations with TRW, Inc. (TRW) to allow TRW to drill several wells on Moore’s property. At negotiations, TRW and Moore orally agreed that TRW would drill no more than six wells, the wells would be placed in areas agreed upon on a map, and TRW would not drill in a large field on the property. At a later date, TRW met with Moore to finalize the written contract. Moore reviewed the contract and proposed revisions. TRW and Moore agreed on proposed amendments and executed the written contract. None of the earlier oral provisions were included in the written contract. In 1990, TRW assigned their rights to Pennsylvania Castle Energy Corporation (Pennsylvania Castle) (defendant). Pennsylvania Castle reached out to Moore to negotiate additional drill sites, but Moore refused. Pennsylvania Castle proceeded to begin construction in the field on Moore’s property anyway. Moore filed suit against Pennsylvania Castle for breach of oral contract and trespassing. The lower court found in favor of Moore, and Pennsylvania Castle appealed.