Power vs Precision

After the post I made last week about gear and attributes in Guild Wars 2, I got not only a great response which I’m truly grateful for, but also had a number of really good questions and discussions with a number of friends and players. This post is the outcome of one of those discussions about the pros and cons of stacking Power over Precision. There’ll be another later about Toughness vs Vitality.

This is going to be a little bit more maths heavy than before (which was mostly just tables of options), but hopefully I can make it simple enough for most to follow without a headache!

How damage is calculated

In Guild Wars 2 according to the Wiki, damage is calculated according to the following equation:

Damage = ( Power * Weapon Damage * Skill Multiplier ) / Target’s Defence

This is just one hit though and on its own it means very little. We need to look at what happens over a number of attacks and that’s where critical chance, critical damage and precision all roll in. In order to investigate the effect of all these mechanics, I’ve had to make a number of assumptions about various values that may not be true in game. For example, I’ve assumed that all weapons deal 1000 damage, the skill multiplier is 2 and the target is a scholar who has done nothing to improve their toughness. Just because the numbers don’t tally exactly doesn’t mean the trends that they tell us aren’t useful – in fact the opposite. To minimise the effect of these assumptions, I’ve changed none of them in any of the calculations.

This means the only factor in the equation we’ll be changing is Power, and we can investigate Precision by looking at a number of attacks and varying the number. So, I have also assumed that the number of critical hits in 100 exactly tallies with the percentage chance to critical hit (ie if the critical chance is 30% then out of 100 attacks, 30 of them will be critical hits).

In the game there are lots of things that affect how much damage an attack does, including things like Might, Fury, Protection, Vulnerability and Toughness, or if it actually lands at all. You can read more about this on the Guild Wars 2 Wiki.

Your actual results will vary. 

The base line

The base line for all professions is 916 Power and 916 Precision. As was explained last time, every point in power equates to a point of attack damage, so by default all characters have 916 attack. Precision relates to the chance to do a critical hit. The first 916 Precision equates to 4% critical chance. Every 21.16 points in Precision thereafter raise the critical chance by 1% (at level 80). The amount of damage a critical attack does is controlled by Critical damage, which is based on 1.5 times the normal attack. Raising critical damage by 1% results in an extra 0.01 multiplier on damage (ie 1.51 times the normal attack).

All in all, a bog standard character will do a normal hit of 998 and a critical hit of 1497. Over 100 hits, on average they will do 101,778 damage.

Raising power

To see the effect of power, I’m going to just run through the calculations of raising it in steps of 200, probably further than is possible through equipment and gear.

Power	Precision	Critical Chance	Critical Damage	1 hit	100 hits
916	916	4	1.5	998	101,778
1116	916	4	1.5	1,216	124,000
1316	916	4	1.5	1,434	146,222
1516	916	4	1.5	1,651	168,444
1716	916	4	1.5	1,869	190,667
1916	916	4	1.5	2,087	212,889
2116	916	4	1.5	2,305	235,111
2316	916	4	1.5	2,523	257,333
2516	916	4	1.5	2,741	279,556
2716	916	4	1.5	2,959	301,778

So looking at the trend here, we can see that an extra 200 points into power will reward the player with an extra 22,222 damage over 100 attacks.

Raising precision

Similar to what we did with power, I’m going to run through the calculations of raising precision in steps of 200.

Power	Precision	Critical Chance	Critical Damage	1 hit	100 hits
916	916	4	1.5	998	101,778
916	1116	13	1.5	998	106,493
916	1316	23	1.5	998	111,209
916	1516	32	1.5	998	115,925
916	1716	42	1.5	998	120,640
916	1916	51	1.5	998	125,356
916	2116	61	1.5	998	130,071
916	2316	70	1.5	998	134,787
916	2516	80	1.5	998	139,503
916	2716	89	1.5	998	144,218

Once again, looking at the trend, an extra 200 points in precision raises the critical chance by 9.45%, resulting in an extra 4,715 damage over 100 attacks.

That’s a big difference

So we’ve established that (for these numbers at least) you’re going to get around 4.5 times more damage putting 200 points into Power rather than Precision. So are there any reasons at all to put points into Precision?

The answer is yes, to a point. There are a number of skills that have effects that fire on a critical hit, so increasing the chance to critical hit is something you want to do – you just don’t want to ignore power so much that your character is very weak. So if you raise your Precision up, you might want to consider raising Power as a secondary attribute to make sure the attacks that do become critical hits do even more damage. Of course, this will mean sacrificing points you can put into your survival or other wanted benefits.

In reality, Power and Precision aren’t mutually exclusive. Many armor and jewellery pieces have both Power and Precision on them in varying proportions. Working out exactly what proportions you need to get the best out of your character isn’t easy (we haven’t factored in condition damage or might for example) but hopefully you’ve now got an idea of which is better for you!

Of course, these aren’t the only common considerations for characters – I’ll be taking a look at Toughness and Vitality soon.

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