# How is Precision used to calculate critical chance?

I am very confused by the Precision attribute. On the Guild Wars 2 wiki it says:

Precision is an offensive character attribute. Attribute points put into precision increase the chance of a critical hit for the character. Many of the conditional effects of a skill or trait trigger on a critical hit.

What confuses me is, how critical strike is calculated from precision. I had previously had 47% chance to critically strike (when I was about lvl 40). I am now lvl 60 and when I looked it says I only have 40% critical chance. I know for a fact that I have way more points of precision now than when I had 47% critical chance.

The only reason for this that I can think of is that the equation to calculate critical chance from precision takes level in account. But I would appreciate if someone give a definitive answer on how critical strike is calculated.

• Did you have any different gear at all at the time? That could (I assume) affect your crit chance.
– Alex
Aug 31 '12 at 11:51
• @Alex, I haven't had any mod that directly increased my critical chance. Only mods that increased my precision. And since my precision is higher now than before, but I have less critical chance, I am curious how critical chance is calculated.
– Jay
Aug 31 '12 at 18:53
• I would also check your traits, as you may have changed from a tree with precision. Sep 4 '12 at 2:54
• @Domocus, I had in fact put more trait points into precision at lvl 60 compared to when I was lvl 40.
– Jay
Sep 4 '12 at 20:51

Your base precision is effectively ignored by the system. Additional critical chance is only provided by precision from your weapons/armor/jewelry/traits.

The amount of additional precision (not base) required to increase the chance of a critical hit by 1% is determined by the following formula, where `Level` is your character level:

``````0.0025 * (Level^2) + (0.05 * Level) + 1
``````

So, at level 80, you gain 1% critical chance every 21 additional precision.

• That doesn't sound right at all. I'm lvl 80 and have 1571 precision. 1571 / 21 is 74.8% crit chance. I have 35%. And where do you plug in precision in that equation?
– Jay
Sep 4 '12 at 20:41
• And for that equation to even get the 21 as you suggested, it's missing some pretty important parantheses.
– Jay
Sep 4 '12 at 20:47
• @jay You have 35% crit chance because it's only ADDITIONAL precision; I added emphasis to my post. You have 916 base precision at level 80, so `(1571-916)/21 = ~31.1`. I assume you have some other crit chance effects to get the extra +4%? Sep 5 '12 at 2:29
• @Corey Csuhta I would assume that the additional 4% crit chance is from the base crit chance that all characters have.
– user31698
Sep 5 '12 at 10:33
• @JonErickson Point to the word "Precision" on your Hero panel. Sep 8 '12 at 5:45

Level absolutely affects critical chance. I'm not sure of the exact numbers, but you'll notice that when you're being downleveled, your downleveled crit chance will be higher than your regular crit chance, despite the fact that you have the exact same armor, and in fact a decreased Precision stat.

Below is the formula that is used to calculate your critical chance. (0.0025 × (Level x level)) + (0.05 × Level) + 1

To explain how it works, if i was lvl 80: 0.0025 * (80 * 80) + (0.05 * 80) + 1 = 21 The number you receive is the required precision you need to get 1% critical chance.

I found the information here: http://wiki.guildwars2.com/wiki/Precision, so as not to appear to be a thief.

• Downvoted since this is almost identical to Corey's answer.
– Jay
Sep 6 '12 at 20:05