Dark Knight: Guide by Raenryong/Logic of Equipment

__TOC__	
=Introduction=
DDing is not a simple task. Many equipment pieces, and the stats on them, are incredibly situational, and whereas anyone can make a mediocre DD, it is useful to know game mechanics and use logic to decide your equipment choices. We will talk about the logic behind gearing for certain tasks.
=TP Phase=
==Preface==
At maximum potential, it is often said that;
Haste > Accuracy > Attack > STR ...
However this is not necessarily true if you are NOT at maximum potential (95% accuracy, strongly buffed). Haste, while very powerful, is useless without the Accuracy to support it, and STR is not as useless as people make it out to be, even for TP phase, for example.
Let us consider each stat in turn.
==Primary Stats==
===Haste===
Increases DoT dramatically; faster hits without a reduction to TP gained per hit, allowing for quicker attacks (greater melee DoT) and more WSs. This is what is known as an INCREASING RETURN stat: the more Haste you stack, the better it gets proportionately!
===Accuracy===
Increases DoT by allowing you to connect more hits (greater melee DoT) and hence produce more WSs (due to more TP gained). This is what is known as a DECREASING RETURN stat: the more Accuracy you stack, the worse it gets proportionately! That's not to say don't use accuracy; on the contrary, it is your best stat besides from Haste in a lot of situations. A common misconception is that any value of Haste is better than any value of Accuracy; accuracy and haste essentially do the same thing, but in reverse; both increase how many hits you put out and how much TP you gain, except one gets better the more you add (Haste) and one gets worse the more you add (Accuracy).
===Attack===
Increases melee DoT by possibly increasing pDif (damage multiplier) -- a very good stat if you can get it in large quantities, smaller quantities often will do little. It does not amplify the rate at which you gain TP though, making it secondary to Haste and Accuracy in terms of increasing overall damage. This is what is known as a DECREASING RETURN stat: the more Attack you stack, the worse it gets proportionately! Again, don't neglect it, but don't sacrifice other stats for it. Deciding between this and accuracy is challenging sometimes. Attack becomes better proportionately as STR becomes better (and by extension, weapon DMG).
===STR===
Increases melee DoT by possibly increasing "base damage" (also may increase pDif if there is enough). Bear in mind however that Dark Knight damage output does not rise very strongly with STR nor with base damage at higher levels. STR does not amplify the rate at which you gain TP, making it secondary to Haste and Accuracy in terms of increasing overall damage. Contrary to popular belief, STR is not always secondary to Attack regardless. Having a good amount of STR is essential for creating heavy damage, though 2handed weapons benefit more tangibly from Attack (STR affects your damage more if the DMG on your weapon is LOW despite the lower fSTR cap); nevertheless, don't take 5 Attack over 3 STR or something. STR has slightly decreasing returns -- but with a plateau at the fSTR cap. You will get slightly decreasing returns as you add STR, until you hit the fSTR cap where your returns will sharply decrease. STR becomes better proportionately as Attack becomes better.
==Secondary Stats==
===Double Attack/Triple Attack===
Haste is better than adding these unless there is a large amount of these stats, because hitting faster gives you more hits for Double Attack or Triple Attack to proc on, so in the end you have the same impact but Haste also helps you when a Double Attack or Triple Attack does not proc. Accuracy does the same but to a slightly lesser degree, making it slightly superior to all but large values of this (Brutal Earring for instance). These stats however are better than anything but accuracy/haste and potentially a very large value of STR/ATK.
===Delay Reduction===
Delay reduction, such as that found on Sword Strap or Suppanomimi is not as potent as Haste since it actually reduces TP/hit, which can potentially reduce WS frequency and hence potentially reduce your overall damage. It is for this reason I do not recommend Sword Strap for Dark Knight, where less number of hits to 100% TP is especially important unless you can achieve this without losing your "x hit" build, where it becomes an option for DoT.
===Store TP===
This is useful if it takes you one less hit to 100% TP, useless otherwise.
==Conclusion==
Building for a DD is not a simple task. There are many considerations, and this may vary by mob. However, here are some guidelines;
* Build for meat if you don't have to compromise your gear too much
* Haste/accuracy are your top DD stats, generally.
* Use an accuracy ring, not a STR one (Rajas Ring is an exception)
* Gear is situational! Carry different builds for different areas if possible
* Gear to reach an "x hit" build if you don't have to sacrifice too much for it: the less number of hits to 100% TP without it impacting your accuracy/haste too much is better
* Generally: 1haste = 2.5acc on a TP build (~3 if you have a lot of haste buffs)
* Generally: 1acc = 3atk on a TP build
* If you are eating sushi, you do not need to gear as much accuracy
=WS Phase=
==Preface==
The common idea between weaponskill damage is STR, STR and more STR. This is not a bad idea but it is also not optimal depending. This section will deal with Dark Knight weaponskills only, do NOT apply it literally to other weaponskills.
Scythe's top weaponskill in most situations is Guillotine. If you are gearing for Spiral Hell, refer to the Spinning Slash section. Cross Reaper is geared like Guillotine but with slightly less emphasis on accuracy.
==Guillotine==
Guillotine is a four-hit weaponskill. If we assume the first hit of the WS is likely to be at 95% accuracy (based on weaponskill testing, the first hit of any WS appears to have a significant accuracy bonus), that means that your odds of landing all 4 hits is (0.95) * (acc%/100)^3.
This means that accuracy is vitally important, as I will demonstrate (all values are given to 3 significant figures);
95.0% Accuracy: 81.5% chance of landing all 4 hits [Upper cap of accuracy] 
90.0% Accuracy: 69.3% chance of landing all 4 hits
85.0% Accuracy: 58.3% chance of landing all 4 hits
80.0% Accuracy: 48.6% chance of landing all 4 hits
75.0% Accuracy: 40.1% chance of landing all 4 hits
70.0% Accuracy: 32.6% chance of landing all 4 hits
65.0% Accuracy: 26.1% chance of landing all 4 hits
60.0% Accuracy: 20.5% chance of landing all 4 hits
55.0% Accuracy: 15.8% chance of landing all 4 hits
50.0% Accuracy: 11.9% chance of landing all 4 hits
45.0% Accuracy: 8.66% chance of landing all 4 hits
40.0% Accuracy: 6.08% chance of landing all 4 hits
35.0% Accuracy: 4.07% chance of landing all 4 hits
30.0% Accuracy: 2.57% chance of landing all 4 hits
25.0% Accuracy: 1.48% chance of landing all 4 hits
20.0% Accuracy: 0.760% chance of landing all 4 hits [Lower cap of accuracy]
Indeed, 95% accuracy gives you an 81.5% chance of landing all 4 hits, but if you even drop a SINGLE accuracy%, 94% accuracy gives you a 78.9% chance of landing all 4 hits. 1% Accuracy loss has resulted in a 2.6% loss of consistency in Guillotine.
From these figures it is clear to see that ACCURACY is your most important stat on Guillotine. However, overshooting on accuracy is not helpful either because every point beyond 95% is entirely wasted.
To gear Guillotine, gear enough accuracy (varies from mob to mob, buff choices, food choices -- I recommend making several Guillotine builds) to have 95% accuracy (slightly above to be safe is fine too) and then use offensive stats. Now, the question is -- which offensive stats?
===STR vs MND vs Attack on Guillotine===
Guillotine has mods of 25% STR and 25% MND. However, contrary to popular belief, Attack is still a very valuable stat on weaponskills.
Weaponskill damage formula = (D + fSTR + WSC) * fTP * Pdif
====STR's role in weaponskill damage====
STR amplifies WSC there at a rate of (25 * 0.83 at level 75) per point of STR (look up WSC if you are confused) and fSTR, with 1/4 chance of increasing fSTR by 1 per point of STR until it is capped though it should be noted that since DRK D is very high, it will not increase overall damage as much as other jobs (since the increase per point of fSTR is 1/(D + (fSTR-1) + WSC)). It is a significant but not unbeatable damage modifier.
====MND's role in weaponskill damage====
MND amplifies WSC there at a rate of (25 * 0.83 at level 75) per point of MND (look up WSC if you are confused). It is therefore relatively insigificant, though still helpful if you can get it without sacrificing other offensive stats for it; also try not to lower it. -mnd will not always lower the WSC and this can be calculated independent of monster (if you are worried about using a Flame Ring for instance).
====Attack's role in weaponskill damage====
Attack amplifies pdif and so multiplies the entire weaponskill's damage; large amounts of attack are VERY valuable.
=====Conclusions=====
* The most important stats on Guillotine are Accuracy and Attack. After these are satisfied, STR is the most important and finally MND is not a concern unless you are getting it in a slot where you do not sacrifice much for it, though try not to lower it. This does not mean always take Attack over STR, especially if you consider that 4STR gives you 3Attack.
* Guillotine is a balancing act. There is no ideal build for all situations. Think about tradeoffs in terms of accuracy loss for offensive gain, and choose the best combinations. Potent Belt vs Warwolf Belt for instance -- 3str 8acc vs 5str 3.75acc. 2str for 4.25acc is not a very good tradeoff when you consider that a 5STR ring vs a 5acc ring is 5STR for 5acc.
* Scythe merits greatly amplify Guillotine since they give both accuracy and attack; buffs are also crucial to Guillotine's power.
* Double Attack is a valuable stat unless there is a very strong other option available. Always Guillotine in Brutal Earring, but don't Guillotine in Askar Korazin for instance.
* If you are eating sushi, put a heavy emphasis on Attack and don't worry about accuracy too much.
* Guillotine CANNOT critical outside of Sneak Attack.
==Spinning Slash==
Spinning Slash is very simple. It has a significant accuracy bonus to its only hit as well as a significant pdif bonus. What does this mean?
* STR is your strongest stat. Substitute Double Attack in areas where you can do so without losing too much power; Brutal Earring is always better than Triumph Earring.
* Ignore INT, just try to avoid lowering it if you can (not a big deal if you do though).
* Attack is not useless but it is devalued. Don't take something like 1str over 10 attack, but don't objectively seek attack either; Hecatomb Harness is better than Haubergeon most of the time.
* Spinning Slash CANNOT critical outside of Sneak Attack.
==Conclusion==
Guillotine is the superior weaponskill when your attack/accuracy are high relative to your opponent, and Spinning Slash is the superior weaponskill when your attack/accuracy are low relative to your opponent. Both are subject to your current build and food choices as well as the monster in question, but generally speaking this is true.
Experiment, and don't be afraid to try different builds!