A rather strange statistic is present on skills, spells and items in Diablo 4. Named "Lucky Hit", its interest and its effects are far from obvious at first sight. We explain how it works in this guide, so you can make good use of it in your builds.
Despite what some people say, equipment requires a lot of choice in Diablo 4, there are plenty of characteristics that compete with each other, with very distinct advantages and bonuses. But to choose what items to equip, what to enchant, and how to optimize your build, it is essential to understand what each stat brings. Blizzard had the good idea to add tooltips under the skills to explain certain effects, such as Vulnerability, but the information on Lucky Hits is limited and not very descriptive, in the end. We will therefore take over, since it is very easy to misunderstand the thing.
The Operation of Lucky Hit Explained
To simplify and use terminology that is likely familiar to you if you've played other high-level hack 'n' slash games or MMORPGs, we could associate "Lucky Hit" with "Trigger Chances" and the famous "Procs." Although in reality, it's a coefficient.
When you inspect an offensive skill in the talent tree (with advanced description enabled), you can see a line indicating the Lucky Hit Chance. These chances tend to be higher on single-target skills compared to AoE ones, as well as on skills with cooldowns rather than those without. Let's take an example with the Druid's skill "Shearing Wind" below, which has a 33% Lucky Hit Chance.
This means that every time you hit an enemy, you have a 33% chance to trigger an additional effect. But what effect? This is where it gets interesting. Through your talents and equipment, you can potentially accumulate dozens of different effects, each with a chance to trigger with every Lucky Hit.
For instance, let's say you have a talent that gives "Up to 10% chance to inflict Vulnerable on a Lucky Hit" and an affix "Up to 5% chance to execute an enemy on a Lucky Hit." This does NOT mean you have a flat 10% or 5% chance to inflict Vulnerable or execute with each strike. Even though both effects, along with potentially others, have a chance to trigger with each strike. When a Lucky Hit triggers (33% of the time in our example), you then have a 10% chance of inflicting Vulnerable and a 5% chance of executing an enemy. It's a chance within a chance: a bit complex!
But don't worry, you can easily calculate your actual chances of triggering a specific effect if you have some basic math skills handy (we're not trying to insult you here). Just divide all the percentages by 100, then multiply them together, and finally multiply the result by 100:
33% becomes 0.33, 10% becomes 0.1, and 5% becomes 0.05.
(0.33 x 0.1) x 100 = 3.3%
(0.33 x 0.05) x 100 = 1.65%
So, you have a 3.3% chance per Shearing Wind to inflict Vulnerable on the target and a 1.65% chance to execute them. It might not seem like much when put this way, but there are solutions.
Improving Your Lucky Hit Chances
There are talents and equipment affixes that enhance your Lucky Hit chances. Let's say you have +20% on an item and +30% from a talent where you've invested a point. We haven't been able to confirm exactly how the game calculates this, but we're fairly certain it's multiplicative and not simply added to your base Lucky Hit chance. Otherwise, reaching 100% Lucky Hit chance on all your skills would be too straightforward, rendering the statistic virtually useless.
Using the example of Shearing Wind with a 33% Lucky Hit Chance:
We divide all values by 100, add the bonuses, and then multiply by the Lucky Hit chance:
0.33 x (1 + 0.2 + 0.3) = 0.33 x 1.5 = 0.495
Multiplying the result by 100 gives the new percentage: 49.5% Lucky Hit Chance.
If we consider the effects mentioned earlier, the new result is:
(0.495 x 0.1) x 100 = 4.95%
(0.495 x 0.05) x 100 = 2.475%
Now you have a 4.95% chance per Shearing Wind to inflict Vulnerable and a 2.475% chance to execute. It still might seem low, but with skills having better base Lucky Hit Chances and effects having higher chances of occurring, you can regularly trigger a specific effect. This makes a big difference for skills used frequently and rapidly, like the Hydra's shots, in practice.
We hope we've been clear. Please don't hesitate to let us know if any points still seem confusing or unclear.
Why Lucky Hit is a Good Thing (Even Though It's Complicated)
If math makes you queasy and theorycrafting isn't your cup of tea, you might find all of this unnecessarily complex and repetitive. But in reality, Blizzard has done players a great service by openly displaying this statistic, for once. Chance-based mechanics have always existed in most RPGs/MMOs/hack 'n' slash games, but they were usually hidden. They were never openly communicated to players, so most people greatly overestimated their chances of triggering effects with their skills. Players who wanted to calculate all of this to optimize their gameplay would have to resort to datamining, ask developers for information (hoping for a response), or spend hours repeatedly using each skill to gather data and perform statistical analysis. None of that is necessary here, as the information is readily available.
Having Lucky Hit Chances is a necessary evil, rather than directly applying the same chances for an effect to occur across all skills. Otherwise, AoE skills would become too powerful, and the same goes for multi-hit skills. Imagine if the Wizard's Hydras, the Necromancer's Skeletons, and the Rogue's Rapid Shot all had a 5% chance to execute a target with each hit? The sheer number of attacks would quickly obliterate everything, even at higher difficulty levels, and such effects would become the uncontested kings in player builds.
In summary, this approach balances different skills and rewards the use of powerful attacks rather than spamming numerous small attacks or AoE. Developers can also incorporate more potent and interesting effects, like a Meteor or a massive Poison Nova, without instantly throwing off the overall balance. Lastly, it potentially allows the creation of builds centered around Lucky Hits, where you carefully choose your skills, accumulate effects, and increase Lucky Hit chances, without making them overwhelmingly powerful right away.