Some weapons and armor come in 'sets' (bandanna + glove, tutu + ballet shoes), signaling about the other humans that fell down like the protagonist did, their belongings now scattered.
In multiplayer, the Artifacts unlocked by all players in the lobby are pooled the team can enable any Artifact that has been unlocked by any of the party members.
Chance of success is based on Locke's current level compared to the level of the monster he's stealing from. Nonetheless, Deltarune is one of the more recent popular artworks to proliferate this hallmark of internet culture.