The Pain Absorber (ペイン・アブソーバ, Pein Abusōba?) is a feature, bundled with the Cardinal System and «The Seed», that nullifies or uses misleads to erase the pain signals that would be generated upon a player's avatar being injured.
In most games that are operated based on The Seed, although the feature can be adjusted, it cannot be turned off entirely. The only exception known so far is ALfheim Online, which is based on a copy of the Sword Art Online servers. In ALfheim Online, the Pain Absorber has ten levels, level 10 being full pain absorption and level 0 disabling the effects of the absorber entirely. If the Pain Absorber is set to level 3 or below, the pain affects the player's real body as well. The Pain Absorber's level can be adjusted via voice commands by a person with administrative privileges.
Another exception is Project Alicization. All injuries the avatar suffers in this virtual reality produces a realistic sensation of pain. Kirito has even commented that the pain felt in this virtual reality could be even greater than the pain felt in reality, as the brain would normally secrete chemicals that would decrease the pain, or end up in a coma as a defensive mechanism.