Invisibility Potion

The invisibility is the least interesting part. The buff drops your aggro through the floor, so in multiplayer enemies pick somebody else, and alone most things simply will not chase you as long as you keep your hands still. It also thins out how often enemies spawn and caps how many can exist near you at once. That combination makes this a mining, building and biome crossing tool rather than a combat one.

Damage of any kind cancels the buff outright, including chip damage you barely notice like a fall or a lava tick. Attacking or using any item pops you back into view for a moment and pulls most of the aggro reduction back while you do it. So the potion is worth close to nothing in a fight. The moment you start swinging you are visible, targetable and paying for something you are no longer getting. You can also cancel it deliberately from the buff icon if you want normal spawn rates back.

Light and particle effects carry on regardless. Sprint trails, the beetles orbiting Beetle armor, your minions, pets and light pets all keep announcing exactly where you are. In multiplayer your head still shows on the map to friendly players. And nothing here stops an enemy that already picked you from firing at your last known position.

These turn up in pots and in chests, which is how most players first meet one. Worth setting aside rather than drinking on sight, because the situations they fix come up more often than the crafting cost implies.

• Crossing the Corruption, Crimson or Dungeon when you have no interest in clearing it.
• Mining in hardmode, where the spawn reduction does more for you than any defensive accessory.
• Building in an area you have not lit or walled off yet.
• Multiplayer, where you want the boss or the mob to commit to whoever is actually built to take hits.