A warranty deed is a legal document that a property owner signs in certain circumstances when transferring their property to a new owner. A warranty deed promises the seller that he or she legally owns the property.A general warranty deed is a deed used to legally transfer real property from one person to another. This type of deed offers the most protection for the buyer. An Illinois warranty deed form is a type of deed used to transfer real estate with a full warranty of title. A warranty deed guarantees that a seller owns the property free and clear of liens. A warranty deed, also known as a general warranty deed, is a legal real estate document between the seller (grantor) and the buyer (grantee). Warranty Deed: This protects the purchaser against all defects in the title and may cover certain specific promises of the seller. An ownership so complete that no other person has any interest in the property. In a special warranty deed, a grantor offers limited protection to the grantee.