Asgard shield

Energy shields are the primary defense technology used by Asgard starships. As the technology was shared by the Asgard with the Tau'ri after their contributions in defeating the Replicators, the Earth-designed Prometheus- and Daedalus-class battlecruisers are also protected by Asgard shields. This gives them great superiority over most other space-faring races in both the Milky Way and Pegasus Galaxy.

Asgard shields create an elliptical "bubble" around the starship that absorbs and diffuses the energy from weapons fire. The shields will gradually weaken under sustained fire, rather quickly if the attack is of sufficient force, allowing energy from attacks to bleed through, causing damage to the ship. Although additional energy can be allocated to the shield bubble to reinforce it, ultimately the only way for a ship to survive a continual attack is to withdraw, and give the shields time to recharge.

Asgard shields are more effective than most Goa'uld energy shields, except when facing foes of an equal or superior technological level. However, the strength of these shields is relative to the power channeled into the shield system. The most advanced shields they had were given to the Odyssey in Unending and this allowed the Odyssey to take multiple hits from Ori ships and be undamaged, something no ship had ever done before.