A special warranty deed provides only limited protection. With the deed, the seller only guarantees the title was clear while he owned the property. Therefore, if defects arose before the seller took ownership, he is not responsible for repairing them or paying damages to the buyer.
The general warranty deed provides the most protection for a buyer. The seller guarantees the title is currently clear of defects and was also clear when he took ownership. This means that if any liens, mortgages, judgments or claims of ownership arise after the buyer takes possession, the seller is responsible for defending against those claims and paying monetary damages to the buyer if owed.
The general warranty deed provides such strong possession because it contains six covenants, or promises, to the buyer. At the time of the transfer, present covenants are: the seller's ownership of the property and the right to sell it, as well as that there are no defects or encumbrances on title. After the transfer, future covenants are: the buyer's guaranteed ownership above all future claims, the seller's guarantee to defend against those claims and the buyer's right of quiet enjoyment, which gives the buyer exclusive right to use the property free of disturbances.