Encumbering Stone

It comes out of Sandstone Chests in the underground desert, so plenty of players own one long before they work out what it is for. Keep it anywhere in your inventory and the game stops handing you things. Nothing you walk over enters a slot, and it makes no difference whether a matching stack is already sitting there. Your Void Bag is shut out as well, so remote storage will not quietly catch what you are refusing. Two exceptions save you: hearts and mana stars still fly in, so you are not switching off your own healing, and anything you reel in while fishing lands normally.

Open a grab bag while the stone is on you and the contents go nowhere, because the game hands those out the same way it hands out floor loot. Crates and boss bags all disappear like this, with no message to tell you what happened, so clear it out of your inventory before you start ripping bags open. Two places are safe to park it. Dropped in the trash slot or stored in a Void Vault it does nothing at all, and it will not even block the vault it is living in.

You do not have to drop it to stop it. Press your open and activate key on the stone, in the hotbar or in the inventory grid, and it flips to an inert version of itself with a name to match. Pickup goes back to normal until you flip it again. Journey Mode is the one place the toggle does not carry across: researching either form registers the blocking one, and that is the form you get back out of the menu.

This is a farming tool. Long grinds throw the same rubbish at you over and over, single stack weapons, banners you already have, accessories you will never equip, and every one of them takes a slot you then have to clean out by hand. Event waves, statue farms and long mining runs like a hellevator are the obvious cases. Switch the stone on and all of it stays on the ground where it belongs. There is no partial setting, though, so turn it off before you kill anything whose loot you actually want.