Merit requirement.
A super with the Weapon X Training Perk may choose to take this background, but nobody else. This attribute represents a piece of equipment that is made of adamantium, a super-hard, virtually unbreakable metal. Wolverine's claws and Cyber's skin were coated with this metal, but an adamantium sword is more common than Body Armor or Body Weaponry.
A weapon made of adamantium has only a difficulty of 4 for the purposes of damage tests (rather than the normal 6). It can cut through virtually anything, and is for nearly all intents and purposes indestructible. Of course, it can be stolen...
Armor composed of adamantium cannot be pierced, even by adamantium in most cases. Full conversion Body Armor (skin-grafts or bonds like Cyber's) requires five points in this Background, and decreases the difficulty to absorb blunt trauma to 5, or piercing damage to 4. As Body Weaponry or Body Armor, Adamantium requires the Healing Factor Power at a minimum Rank equal to the rank of the background. Otherwise, if the super takes simple skin grafts but does not get five points in this Background, there are still a number of benefits. Punches or kicks from adamantium-sheathed fists and feet are diff 4, and body parts covered cannot be successfully targeted for extra damage from called shots, crits, etc. Moreover, unarmed parries of weapons are possible.
An adamantium-bonded skeleton, like Wolverine's, is unbreakable. It will stop many blows (crushing attacks to the ribs can't really harm the character) and also give an automatic damage success in brawling.
If the super has a healing factor and he took Body Armor or Body Weaponry with this Background) its effective level is reduced by the (level of the background -1) to a maximum loss of 3 levels. Thus, the Adamantium Skeleton would reduce the effective level of a Healing Factor by 2. Therefore, a normal human healing ability is insufficient to handle adamantium beyond level one. If the Healing Factor is reduced to below zero, the super does not survive the bonding process. Internal implants (like skeletal bonding) increase the prerequisite level of the Healing Factor (though not the loss of effectiveness) by one.