Diablo 4 brings tons of new mechanics to the franchise, one of the most well-received has been the Codex of Power. While these mechanics bring a lot of variety into the game, they may take a bit of explaining. Lucky Hit is definitely one of those mechanics; even returning Diablo fans might not know exactly how it works.
Lucky Hit may seem simple at first, but when you dive into the numbers, there's a lot of complexity at play that you'll need to understand if you want to utilize it in your build correctly, especially when you factor aspects and the limitations of the specific weapons with those aspects into the mix. For example, how does the game calculate multiple Lucky Hit effects, and what does Lucky Hit Chance Bonus actually increase? Here's everything you need to know about the Lucky Hit mechanic in Diablo 4.
Updated by Chad Thesen on July 15, 2023: This guide has been updated to feature new embedded links that can allow easier navigation for readers. These embedded links include a list of aspects and a guide on weapons that will be useful when building the rogue class builds with a very heavy focus on Lucky Hit. This will be great for players looking to run a character with this very specific style of play.
How Lucky Hit Works
At its core, Lucky Hit is a bit similar to critical strikes except that the effects that can happen on a Lucky Hit are determined by your skills and equipment. Instead of dealing extra damage like a critical hit or overpower would, Lucky Hits acts as a way to allow other effects to happen on a hit. However, there are a few issues with this comparison, and they all come down to the difference between Lucky Hit Chance and Lucky Hit Effects.
Most skills have a base Lucky Hit Chance which you can see by turning on advanced tooltips in the game settings. This Lucky Hit Chance is an estimate of how likely a skill is to cause a Lucky Hit. If your basic attack has a 50% chance to Lucky Hit, roughly every other attack should be a lucky one, but that doesn't mean you'll be triggering effects left and right.
Again, Lucky Hit does nothing on its own. Instead, it needs at least one effect that happens on a Lucky Hit as well to actually do anything. You can get this from a wide variety of skills and equipment, but you'll likely notice one constant between all of these. They all say that the effect has a chance to happen on a Lucky Hit, not that it happens automatically.
This is the biggest departure from critical hits: Lucky Hit effects all have a chance of happening on a Lucky Hit; they're not guaranteed. So if you have a 50% chance to deal a Lucky Hit, and an effect has a 30% chance of happening on a Lucky Hit, it only has a 15% chance of occurring on any given hit.
If you have multiple effects that could happen on a Lucky Hit, they are all calculated separately from one another whenever a Lucky Hit happens, and Lucky Hits can happen on damage over time ticks, but the tooltips for damage over time skills average the chance of a Lucky Hit happening at all during the entire damage over time effect.
How To Build Around Lucky Hits
The separation between Lucky Hit Chance and Lucky Hit Effect Chance can make it challenging to build around Lucky Hits in a meaningful way. You can boost your Lucky Hit Chance, but there isn't an easy way to increase the chance of an effect occurring, so if that chance is already very low, you'll never be able to make it happen consistently.
Gear can come with an additional Lucky Hit Chance Bonus, but this only increases the chance of a Lucky Hit happening, not of an effect activating. If you want to run the numbers, the formula for a Lucky Hit Effect to go off looks a bit like this:
Lucky Hit Chance x (1 + Lucky Hit Chance Bonus) x Lucky Hit Effect Chance
Using the numbers from above and assuming a Lucky Hit Chance Bonus of 50%, it would look something like this:
0.5 x 1.5 x .3
For a total of a 22.5% chance of the effect happening on any given attack, and this shows why it can be hard to build around Lucky Hits. Lucky Hit Chance Bonus applies multiplicatively to Lucky Hit Chance, so you need a significant bonus to see any sort of meaningful results, and you'll never be able to hit 100% if the skill isn't already at that point.
On top of this, the Lucky Hit Effect Chance will almost always be the limiting factor in this equation, meaning you'll have to find an effect with a decent chance to activate on an item, or it simply won't become consistent no matter how much you try to make it work. Higher caliber of gear will make this even more effective. With most of the powerful Lucky Hit Effects having a low chance to activate, it can be tough to find a good effect to focus on a build. Instead, try to work in Lucky Hit as a sort of spice in the build, adding important elements but not being relied on for the build to function.