Aegis is a tier-4 aura that costs 84,000 Membership Loyalty Points. It is a shield that can block up to 10% damage, based on players' Defence levels. The absorption rate is also consistent with the player's level. For example, at 99 Defence, if the player incurs 50 damage, they are only hit for 45, and 5 is absorbed. The animation, however, only occasionally activates.
The aura remains activated for 30 minutes or until it has soaked up 80,000 life points (i.e. be damaged by a total of 800,000 LP at 99 Defence) of damage, and has a recharge time of 5 hours. When the aura has absorbed the maximum amount, the message displayed in the chatbox is "Your aegis shield has absorbed all the damage it is able to absorb, and has dissipated."
It should also be noted that the aura can stop all forms of damage, and is currently the only way in the game to consistently lower typeless damage. All other forms of reductions that can lower typeless damage are activated by chance, including the Warpriest of Saradomin armour or Warpriest of Zamorak armour's set effect, Defenders and the Leviathan ring.
Aegis is a reference to the shield created by Hephaestus, and worn by Zeus and daughter Athena in Greek mythology. Aegis also means "protection" or "support".
Prior to the Evolution of Combat only 1,000 damage was absorbed. After its launch, the aura absorbed a total of 4,000 damage, before again having been changed to its current state.