A team of modders has created a way to play the single-player RPG Deltarune cooperatively with friends, filling a gap left by the game having no official multiplayer mode. The Deltarune Local Multiplayer mod, led by a developer known as Yomsmam, lets up to three people play through the game together, adding a social dimension to a title normally experienced solo.

Rather than allowing shared control throughout the whole game, the mod limits multiplayer to combat encounters and minigames, where each of the extra players takes charge of a party member such as Susie or Ralsei. During battles, players act on their turn and must dodge enemy attacks individually, represented by coloured hearts, which makes fights both harder, due to more targets for enemies to hit, and potentially easier if everyone dodges well, since it can generate resources quickly. The mod already works across all five currently released chapters and is expected to be updated when Chapter 6 launches next year.