- "Press the attack button to generate an acid barrier and block incoming shots! Try it while the Power Gear is active for a super-corrosive barrier that melts enemies!"
- —Mega Man 11 description (Mega Man)
Acid Barrier is Acid Man's weapon in Mega Man 11. It generates a large ball of acid around Mega Man that protects from all harm, but it shrinks a little every time he takes damage. As long as the acid shield is up, Mega Man can also shoot globs of Acid at enemies, but each shot also makes the shield shrink a little.
Using the Power Gear, the shield becomes more durable and deals more damage, and will automatically shoot at enemies if a projectile hits it.
Just like the other Special Weapons in Mega Man 11, Acid Barrier gives Mega Man new Head Gear and Arm Gear that alters his physical appearance when equipped, rather than simply swapping his colors. The Head Gear is a helmet that encases Mega Man's head in green gel and features a gas mask, much like Acid Man himself, and the Arm Gear is a buster that looks somewhat similar to Acid Man's.
- Acid Barrier is the first shield-type weapon in the classic series to deviate from the usual formula for shield weapons; rather than having projectiles orbit around Mega Man, it envelopes him inside a large ball of damage-absorbing acid that has him shoot globs of acid in place of his Mega Buster.
- It's also the first and only weapon in Mega Man 11 to be leaked officially on the Mega Man 11 website first, before any other internet platform.
- Acid Barrier is similar to Rolling Shield in its charged form, as both generate a shield that temporarily protects the user from all damage.
- Acid Barrier's acid shots might be a reference to Acid Burst since Acid Man could be an homage to Toxic Seahorse.
- Acid Barrier is the only weapon in the series so far that has Mega Man's mouth concealed.