Acid

Ammunition

 * Acid concentrate, an ammunition type in Fallout 4.
 * Canisters of acid, an ammunition type in Fallout Tactics.

Weapons

 * Acid Soaker, a weapon in the Fallout 4 add-on Nuka-World.
 * Acid grenade, a thrown explosive in Fallout Tactics.
 * T86 acid sprayer, a trap found in Fallout Tactics.

Other

 * LSD, a mentioned-only chem, mentioned in Fallout 2, Fallout: New Vegas, and Fallout 4.
 * Hydrochloric acid, a quest item in Fallout 4.
 * Acid (Fallout 4), a crafting component in Fallout 4.
 * Acid (Fallout 76), a crafting component in Fallout 76.
 * Bulk acid, a junk item in Fallout 76.
 * Waste acid, a junk item in Fallout 76.