Gray Matters

 is a perk found in the data files of the Fallout 3 add-on Point Lookout. It doesn't appear in the game and can only be obtained with console commands.

Bugs
Although the description for this perk states that it will reduce head damage by 25%, the effect of the perk instead reduces head damage to 25%, or in other words a 75% reduction in head damage.

Behind the scenes

 * The term gray matter is used for one of the two major components of the central nervous system (along with white matter).
 * The perk may have been associated with the Lump of Brain obtained from the Duchess Gambit engine room after dealing with Tobar.
 * The perk may also have been associated with A Meeting of the Minds, possibly as a reward for helping Calvert and killing Desmond.
 * This could be the second half to the perk Adamantium Skeleton, where it only has a 25% resistance to limb damage.

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