If there is one thing Baldur's Gate 3 players know, it is that Sacred Flame, Shadow Heart's attack-starting cantrip, actually rarely hits. Players have been trying to figure out the arcane mathematics behind this most cursed of spells.

This morning, however, I stumbled across a thread on the game's subreddit that dismissed Sacred Flame's inaccuracy as a mirage and supposedly found the culprit. While that conclusion does not seem to be exactly correct, my own research has confirmed that the Baldur's Gate 3 spell tooltip is indeed buggy, and may have even been so for several months.

But first, if you're not familiar with tabletop systems, you're going to need some very tedious technical details to understand what's going on here. To bear with me, do the constitutional savings projectile.

There are, broadly speaking, two types of attacking actions in D&D 5th edition. These are either an attack roll against the armor class or a throw to withstand. Many spells require the latter.

A saving throw is a roll made against what the spell's target calls the "spell saving DC."

As UncommonEra emphasizes, the problem is that the tooltip for every single spell that requires a saving throw is buggy: "The tooltip says that your spell save DC is not your spell modifier (usually WIS), but your DEX modifier It says it is based on.

I thought that couldn't be true, so I jumped into the game and tried it myself. As it turns out, the truth is more complicated than I thought. It is even more infuriating.

How I tested this theory was with the cleric's cantrip, Sacred Flame. Sacred Flame forces a dexterity save throw against the caster's spell save DC.

Both the target's dexterity and the caster's wisdom were verified to be 10. This means that at level 1, the target is trying to roll a 10 or better on the dice. In other words, the UI should indicate a 45% chance that the spell will succeed (the target will succeed on 11 out of 20 sides of the die). So.

Then the target's dexterity was adjusted and the number changed accordingly. Similarly, I kept the dexterity the same, but changed the wisdom of the caster. To show my work, all the results were as follows:

But in both cases the DC of the tooltip was completely incorrect. The game is indeed lying by accident. As the author of this thread confirms, the tooltip is based on the dexterity of the caster, not the wisdom of the caster, which is completely incorrect.

To analyze this further, I prepared a Banishment with the same character using the charisma saving throw.

So the mystery was solved. The spell's save DC on the tooltip is lying, but the game shows the success probability correctly, right?"

I noticed that the hit probability of Tasha's Hideous Laughter was inaccurate, showing a 56% success probability, and here comes this turbulent quality -29.

I spent the next few minutes tearing my non-existent hair out trying to replicate this phenomenon, and I think I know what's going on.

In the example given, the opponent rolls +6 against DC 22. In this case, the dice would have to roll 16 or better, which would give a success rate of 75%.

I think what is happening here is that "Turbulence-Quality-29", a good warlock, is overlooking that the target has an advantage, i.e., he is rolling two 20-sided dice and choosing the higher one. Mathematically, this would add a +5 modifier to the roll for statistical reasons.

I cannot fault this. Because when I had Gail cast a spell based on dex save against a party barbarian during testing, I was equally confused.

In any case, this would give the target a +11 roll to defeat the DC22, which would give the target about a 45-46% chance of making the save and a 55-56% chance of the spell hitting, as indicated by the mouseover.

This may have given you a headache (where are my painkillers?), but the gist is this: as long as you don't mind the tooltip, it's fine. The mouseover values are still correct, and everything rolls correctly in the combat log. Still, judging from this thread from about 6 months ago, this is a bug that has been going on for some time.

Despite having so many glowing words to say about Baldur's Gate 3, this is a huge failure from a UI standpoint, and it is a bit puzzling that it has been left in place for so long. I am familiar with the D&D 5e ruleset and was not affected, but new players trying to figure out why Sacred Flame does not land may be completely led astray and end up with a completely wrong understanding of how the spells in this system work. Hopefully, patch 7 will address this issue before more players are led down this cursed path.