For those who don’t know, the way crit reduction resistance is calculated is currently broken. The following contains a lot of boring math, so I’m **bolding** the important bits.

Resistances for most abilities are currently calculated by multiplying the debuff by the resistance, and then multiplying the affected stat by that effective debuff. For example, if a dino uses a 50% distraction move against a dino that has 50% distraction resistance, 50% distraction x 50% distraction resistance = 25% effective distraction. Therefore the affected dinos attack is only reduced by 25%, or multiplied by 0.75 (100% - 25% = 75%). This is the debuff calculation working properly.

**Unfortunately, Critical Hit chance reduction (crit reduction) does not seem to work the same way as other abilities, and is seemingly not being calculated correctly.** If you remember before update 2.6 when they set a bunch of dinos crit chance to either 100% or 0%, any crit reduction resistance less than 100% always resulted in a 0% crit chance after being attacked by a cunning attack (the only attacks that reduce crit chance, and always by 100%). This means that **instead of multiplying the crit reduction by the crit reduction resistance, and then multiplying the dinos base crit chance by this effective crit reduction, they were doing something else. By my best estimate, the actual formula instead subtracted the crit reduction from the base crit chance and then subtracted the effective crit reduction from the dinos base crit chance rather than multiplying them.** So for a dino with a 40% crit chance and 50% crit reduction resistance, 100% crit reduction - 50% crit reduction resistance = 50% effective crit reduction. 40% crit chance - 50% effective crit reduction = -10% crit chance, which would just be presented as 0%.

This is the reason for the 2.6 crit changes. **The only cases which were actually being calculated correctly were for 0% and 100% crit reduction resistance… so instead of actually fixing the calculation, Ludia just made these the only options.** Well… until 2.10, when **we got three new dinos with crit reduction resistances between 0% and 100%** (Argenteryx, Glyptoceras, and Rinchicyon). Yeah, they must have forgotten about their little “hot fix” back in 2.6, **so now that good ol’ crit reduction error is back!**

So **if Ludia insists on having dinos with crit reduction resistances between 0% and 100%, this time, they need to actually fix the calculation.** Instead of the current formula, the formula needs to have the effective crit reduction multiplied into the base crit chance. For the above example, it should have 40% crit chance x 75% effective crit reduction = 30% crit chance. **If Ludia only uses 100% crit reduction moves, the formula can be as simple as base crit chance x crit reduction resistance.** A dino with 100% crit reduction resistance multiplies their base crit chance by 100% to keep their full original crit chance (e.g. 40% x 100% = 40%). Or a dino with 0% crit reduction resistance would lose all of their crit percent (e.g. 40% x 0% = 0%). Or a dino with 50% resistance would lose half of their crit chance (e.g. 40% x 50% = 20%).

**But if Ludia ever wants, for example, 50% crit reduction moves, we need a more complicated formula.** After some trial and error, myself and others have determined that this formula is Base Crit Chance × (100% - Crit Reduction × (100% - Crit Reduction Resistance)).

For a dino with a base crit chance of 40% with a crit reduction resistance of 75% against cunning strike (-100% crit chance), here’s how it works:

40% × (100% - 100% × (100% - 75%))=

40% × (100% -100% × 25%)=

40% × (100% -25%)=

40% × 75%= 30%

For a dino with a base crit of 20% and a crit reduction resistance of 50% against a crit reduction of -50%, here’s how it works:

20% × (100% - 50% × (100% - 50%))=

20% × (100% - 50% × 50%)=

20% × (100% - 25%)=

20% × 75%= 15%

**So there’s your formula @Ludia_Developers (@Ned ):**

**Base Crit Chance × (100% - Crit Reduction × (100% - Crit reduction resistance))**

As long as crit reduction is a negative value, it should work for any combination of base crit chance, crit reduction, and crit reduction resistance. Now you have the freedom as a developer to use whatever values you want for these. You’re welcome.