A popular set of Dungeons & Dragons house rules gives players a chance to instantly craft their own allies and enemies in an instance.

Earlier this year, Geek & Sundry writer David Nett shared a set of house rules for his games of Dungeons & Dragons that have gone viral online multiple times. The rules allow players to declare that they "know a guy" and instantly create an NPC with connections to their character. After creating the NPC, the DM then takes control of the character and has the player make a Charisma check to see how the NPC reacts to seeing the character.

As explained by Nett in the original tweets below, the rule was meant to mimic the introduction of Lando Calarissian in The Empire Strikes Back, when Han expresses uncertainty about how Lando would actually greet Han when he approaches Lando for help. Not only does this give players a chance to instantly flesh out some of their backstory, it also gives DMs more characters that can become central to a storyline later on.

The full explanation of the house rule can be seen below:

Because a few ppl have asked about my house rule, “I Know a Guy:” it’s meant to create that moment in ESB when Han decides he can go to Lando for help, but isn’t 100% sure how Lando will actually receive him: 1/ #dnd — David Nett (@davidnett) March 27, 2018

In any situation (where it makes sense), a PC can declare “I know a guy,” and then quickly sketch that NPC & the relationship. Fewer details are usually better - that leaves room for the DM & PCs to play. 2/ #dnd — David Nett (@davidnett) March 27, 2018

Upon declaration, the NPC exists. Then, when the PCs try to interact w the NPC, the player who created that NPC makes a Charisma roll to see how the NPC reacts. Depending upon the situation, the DM may decide advantage/disadvantage applies. 3/ #dnd — David Nett (@davidnett) March 27, 2018

I’ve found this simple and very loose mechanic invites players to create critical NPCs AND continue developing (revealing) backstory as they play. Now it belongs to the world (if you wanna try it). 4/4 #dnd — David Nett (@davidnett) March 27, 2018

Nett's rules have been shared countless times on Twitter and Facebook, most recently by D&D franchise creative director Mike Mearls, who praised it as adding action and uncertainty to the game. Others have suggested certain additions to the rule, such as limiting how many times a player can use it based on that player's Charisma modifier.

What do you think about this D&D house rule? Let us know in the comment section!