Larian used popular homebrew D&D Rules for Baldur's Gate 3 : 'We thought--okay, maybe we could try it too. Some people do it.

Baldur's Gate 3 has a lot to offer if you're a fan of Dungeons and Dragons 5th Edition, the tabletop ruleset on which it's built. While it's a faithful recreation of the rules, it's also got enough homebrew nonsense in the form of magic objects and tweaks to TTRPG's core system to make it stand out.

The decision to keep, change or scrap something hasn't always been easy, as Swen Vincke, Larian Studio co-founder, and Nick Pechenin, design director, revealed during a panel retrospective at PAX West this weekend.

Pechenin said, "We literally searched forums for homebrew rule ideas... like the rule that you can't cast a full-action spell and a bonus-action spell in the same turn." Uninitiated players may not know that D&D's economy of action gives them movement, an action and a bonus. Spells that require a bonus action are available, but using them typically locks you out from casting any spells more powerful than a simple cantrip in the same turn.

It's pretty common for homebrews to throw that rule out the window. Even Critical Role, a livestream game popular enough to get a crowdfunded animated show, had a similar tweak in its first campaign. "[That] rule was just something that often fell by the wayside. So we were like - okay, we're ok, some people do it so maybe we can also try it."

Vincke also jokes about the homebrew rule the team experimented in its early years: "We had a version--we declared, 'These are our homebrew Rules', but then we saw that the community didn't agree. It was a very interesting time in our careers.

I'm guilty of this, but I'm glad Larian changed some of these rules. Cantrips that could be cast indefinitely, like Firebolt, would leave damaging surfaces. This made them superior to some 1st level spells (which require you to use your limited spell slots). Hiding was a bonus action that everyone could use, which took away from the rogues' skillset. My inner rules lawyer still shivers--perish that thought!

It was sometimes the opposite. Larian tried to faithfully replicate OG mechanics, but for whatever reason, it didn't work. Vincke says, "We also had a cover-system, remember that?" In 5th Edition, being behind cover makes it harder to be hit. It adds a bonus to the armour class and also adds that bonus to dexterity save throws. Baldur's Gate 3 does not have cover beyond the physical environment that blocks the line of vision of certain spells or attacks.

Pechenin says that the team "really messed around with it a lot, because it is part of D&D ruleset. But we found so many issues with how it worked in 3D from a top down camera."

The game's response system was also altered primarily as a result of community feedback. During early access players had to toggle reactions pre-emptively on their turn. This made some spells and features worse. For example, you could choose not to cast Hellish Rebuke when attacked by a Fire Elemental (since they are usually resistant to or immune to the damage type), but keep the option for the mage that summoned them.

Pechenin explains that the reaction system was implemented because it was something the community wanted. "That's an example of something we added to early access that was not planned." We really hoped we could get away without pausing the game, because it's difficult technically and things like sound really bad when you stop them.

Baldur's Gate 3 has a lot of this kind of stuff. For instance, 5e grappling is absent and replaced by bonus action shoves. But as a rules geek myself, I find it fascinating to see what concessions you need to make when translating a TTRPG into code. This is bound to present its own challenges, such as figuring out how you can stop the camera from zooming in on goblin feet.