Goa'uld personal defense shield
Shield of energy used by many Goa'uld System Lords for personal defense. Personal defense shields are presumably smaller versions of standard Goa'uld force shields, which operate on an oscillating frequency principle.
The strength of a personal defense shield is directly proportional to the amount of kinetic energy directed at it. Bullets and blasts from energy weapons are therefore stopped, while slower-moving weapons (such as a thrown knife) can pass through.
The Nox - Apophis uses his personal defense shield to avoid capture by SG-1.
Secrets - Heru'ur activates his defense shield after SG-1 arrives to ambush him via the Abydos Stargate. O'Neill defeats it by throwing a knife through.
The Devil You Know - Sokar initiates his own defense shield before Apophis can eliminate him with a staff blast.
Absolute Power - O'Neill turns on Dr. Jackson to prevent him from destroying Moscow in a dream sequence, but the scientist is protected by a personal defense shield.
Enemies - Apophis's only salvation from a band of hungry Replicators is his personal defense shield, which does not aid him when his ship is incinerated in Delmak's atmosphere.