For Honor Stats and Builds

Most of the stats are straight forward, but some not so much so here are the descriptions as given by Ubisoft. Included are some rough expectations of how the stat actually impacts the game, but the disclaimer being that it affects all characters equally in terms of the percent impact and that the numbers themselves are rough estimates and may not be totally accurate, but it should be enough to give an idea of what you're actually getting.

Weapon Part 1
Throw Distance - How far you can throw somebody (That's X+X where the first X breaks their block and the second X is actually your throw) *Minimum -10% Distance, Maximum +10% Distance*
Revenge Mode Attack - The amount of boost to your Attack while in Revenge Mode. *Base +30% Damage, Minimum +15% (-15% from Base) Damage, Maximum +100% (+70% from Base) Damage*
Revenge Gain from Injury - How much Revenge Meter you gain from being successfully damaged. (This does not count chip damage you can take through your guard) *Minimum -33% Revenge Gained, Maximum +33% Revenge Gained*

Throw Distance seems the most useful here if you have decent throws such as the Raider who has some of the longest throws in the game, but you increasing Throw Distance can potentially work against you in terms of follow-up attacks meanwhile some characters benefit from reducing Throw Damage in terms of follow-up attacks, but obviously lose distance that can miss a ledge kill or impact stun. Ideally you don't want to take a lot of direct damage so Revenge Gain from Injury has a clear sense of being the worst stat intrinsically, but there's a clear benefit if you know you get hit a lot as Revenge Mode does give clear advantages regardless of skill level when activating it. Revenge Mode Attack can certain help if you play a weaker standard character normally geared towards Defense and tend to block and counter-attack rather than being overly aggressive or if you simply don't find yourself using throws very often.

Weapon Part 2
Feat Cooldown Reduction - How long your Feats take before you can activate them again. (Feats are what Ubisoft calls your skills, each character gets 4 of them and they have to be activated each game by leveling up.) *Minimum +20% Cooldown Time, Maximum -35% Cooldown Time*
Revenge Mode Defense - The amount of boost to your Defense while in Revenge Mode. *Base -10% Damage Taken, Minimum +15% Damage Taken, -40% Damage Taken*
Revenge Gain by Defense - This is how much Revenge Mode you earn through Block and Parry. *Base is roughly 15 blocked hits one on one until Revenge, Minimum -30% Revenge Gained, Maximum +40% Revenge Gained*

Feat Cooldown Reduction is by far the most useful if everybody is where they should be and most of the fights end up one on one or in your favor. Revenge Gain by Defense is the best way to gain Revenge Mode, while it makes it difficult to enter Revenge one on one still it heavily mitigates a lot of the advantages the enemy gets in 2v1 matches so you can hold out for an ally or kill both of them whichever the case may be. Revenge Mode Defense is helpful should you gain Revenge Mode, but makes it that much harder to enter Rage Mode to begin with and if you die before entering Rage Mode then you're not getting any benefit anyway, so I personally would steer clear of it unless you're heavily geared towards gaining Revenge Mode through other means such as through Injury and a lack of faith in your own abilities. Keep in mind that certain passives have a refractory period before they can be passively activated again such as Auto-Revive, Feat Cooldown Reduction does shorten that refractory period.

Weapon Part 3
Attack - How much Damage you deal. *Minimum -5% Damage, Maximum +20% Damage*
Defense - How much Damage you receive when successfully Damaged. (Successfully Damaged doesn't count chip damage through a block, damage from DoTs, damage from Feats, or fall damage.) *Minimum +10% Damage taken, Maximum -30% Damage taken*
Stamina Cost Reduction - How much Stamina your actions take up. (Any action YOU perform will have its Stamina Cost reduced an action taken by an opponent will not be reduced such as if your attacks are successfully parried.) *Minimum +10% Stamina Usage, Maximum -40% Stamina Usage*

All of these are useful so obviously they make you choose what type of character you want here. Why Defense is on a Weapon Part is beyond me, but you have to choose whether you're Damaging, Defensive, or whether you want to chip away through multiple attacks. An offensive character you need attack, but you also need to make sure you at least have enough Stamina to execute your combos, recovering from Exhaustion has numerous negatives so being able to fully execute your combos without going into Exhaustion is clearly important. Defense is important if you want to stall and you know you can't block the majority of Attacks. Stamina Cost Reduction is mainly for those who want to counter after successful Blocks or Parries which primarily use Quick Attacks rather than Heavy Attacks characters like the Warden are adept with Quick Attacks and may prefer this over Attack as well as Defensive characters such as the Warlord who prefers to counter and don't have large Stamina heavy combos and would prefer to use their short combos more often between successful Blocks or Parries. Keep in mind this is probably the most important piece of equipment so choose wisely. *Notice how the effect of Attack is smaller than the effect of Defense, theoretically this means that Defense is more efficient however you must consider that the goal is to avoid taking direct Damage which would mean that objectively Defense should be the weaker stat as you don't want to use it and the fact that any time you attack you are using the boosted Attack. From an offense perspective if you expect to trade blows Defense is better to have so a character like the Shugoki or Warlord might find that they prefer Defense over Attack to be able to do this more viably as they're both characters that can avoid being interrupted by being Attacked when Attacking.*

Arms
Block Damage Resistance - Lowers the Damage taken by Heavy Attacks through your Block. *Minimum +50% Damage taken, Maximum -50% Damage Taken*
Revive Speed - How fast you revive allies. (Revive Feat is approximately -66% Revive Time even with the Minimum) *Base takes about 3 seconds, Minimum +5% Revive Time, Maximum -33% Revive Time*
Stamina Regen - How fast you recover lost Stamina. *Minimum -10% Stamina Regen, Maximum +35% Stamina Regen*

Pretty straight forward with the exception of Block Damage Resistances which has an impact that looks large, but the actual Damage mitigation tends to be minimal as little actual Damage tends to go through the Block. There are some exceptions with some of the heavier hitters like the Raider which tend to deal far more Damage comparatively through the Block than the more agile characters which may only deal +/- 1 Damage per strike.

Chest
Execution Health Regen - How much Health you regain after a successful Execution. *Minimum -5% Health Regen, Maximum +10% Health Regen*
Block Damage - The amount of Damage you deal with your Heavy Attacks through an opponent's Block. *Block Damage seems to affect how much you stagger the opponent, but also increases damage however it is only noticeable on characters that deal noticeable damage as the threshold is too low to change the damage values either way on certain characters which means it's somewhere under 50% both ways and Damage is rounded to the nearest whole number so dealing 2.4 damage deals 2 damage and 1.6 deals 2 damage.*
Sprint Speed - How fast you move when you Sprint. *Minimum -10% Speed, Maximum +10% Speed

Execution Health Regen is great, but requires time and there is often other ways to gain health and with all the people desperate to get a kill they get stolen quite often through your own team attacking you trying to get the final hit in so they get the kill. Block Damage is helpful for those characters that are Attack focused characters since that extra Damage through a Block can end up saving you several Attacks, any character that invests heavily on Stamina Cost Reduction can make use of Block Damage and take advantage of a sheer number of blows using that recoil to create more openings favoring the chip style of play. Sprint Speed is universally helpful, being able to outrun your opponent lets you either escape danger or chase down a dying opponent and unlike Execution Health Regen it's consistently useful.

Helm
Debuff Resistance - Reduces damage from DoTs such as Bleed or Burn.
Revenge Mode Duration - How long Revenge Mode lasts. *Base lasts about 8 seconds, Minimum -20% Duration, Maximum +40% Duration*
Exhaustion Recovery - How fast you regain Stamina when Exhausted. *Minimum +10% Time to Recover, Maximum -50% Time to Recover*

Exhaustion Recovery is important as if you're exhausted and take Damage you are stunned, a successful Parry will knock you down, and you can't perform Combo Attacks. Revenge Mode Duration is useful if you buff Revenge Mode or buff gains to enter Revenge Mode so you can reap it's benefits longer, but more often than not you either die or kill them before Revenge Mode ends given it's innate bonuses to Attack, Defense and infinite Stamina. Debuff Resistance is useful against certain characters, but doesn't always apply a benefit. Your own team can apply debuffs to you trying to kill steal and the Bleed status effect does far more than simply getting hit by your own stupid teammates.

General trends in terms of importance.
Weapon Part 1
Throw Distance > Revenge Attack > Revenge Gain from Injury.
Throw Distance being the most important since it's always active and that can be either to increase it or decrease it on a character to character basis. Considering you don't want to get directly injured Revenge Gain from Injury ideally shouldn't ever be prioritized.

Weapon Part 2
Revenge Gain from Defense > Revenge Mode Defense > Feat Cooldown Reduction
Defense is the best way to gain Revenge Mode and boosting it lets you more realistically gain Revenge Mode in a one on one basis. Decreasing Revenge Mode Defense can actually increase the Damage you receive upon entering Revenge Mode making it a negative from a Defense survivability standpoint. I'd try to avoid decreasing Revenge Mode Defense since you're primarily going to be outnumbered when entering Revenge and the likelihood is you're going to take a few hits and taking 15% more Damage can easily be fatal even with the added Shield.

Weapon Part 3
Stamina Cost Reduction > Attack > Defense
Stamina Cost Reduction tends to have a most significant impact on Offense additionally has impacts on Defense, but at the same time it's offensive benefits are dispersed over a longer period making Attacking more sustainable, but not increasing the Damage on a per combo basis. Defense has a higher net impact one for one, but stronger players will benefit more from Attack.

Arms
Stamina Regen > Block Damage Resistance > Revive Speed
Stamina Regen is by far the best option here for every single character without question. Block Damage Resistance can be completely insignificant, but is useful against some characters meanwhile the reducing Revive Speed is pretty much completely negligible.

Chest
Sprint Speed > Execution Health Regen > Block Damage
Sprint Speed has a number of benefits from fleeing danger to capping control points even if the benefit is fairly negligible it can be a life saver. Block Damage is really only useful for stronger characters so while Execution Health Regen is pretty insignificant either way if you don't benefit at all from Block Damage a small benefit is better than nothing and you generally want to execute enemies regardless of you Health as it gives Renown, keeps them from being able to be revived, and restores Stamina.

Helmet
Exhaustion Recovery > Revenge Mode Duration > Debuff Resistance
Exhaustion Recovery as a benefit is hugely significant so whilst you want to avoid going into Exhaustion halving the time when taken as a benefit at max is hugely significant, but you could max Revenge Mode Duration should you be heavily focused on Revenge Mode instead and be alright. Debuff Resistance is pretty much entirely useless unless they don't patch the fact that it lowers the stun after you've been parried.

Vikings
As a whole the Vikings tend to have strong side stances while their vertical stances tend to lack reach. The Vikings also tend to be on the slower side when comparing like categories i.e Vanguard to Vanguard, Assassin to Assassin, etc as a trade off they tend to have more power in each of these categories. Typically a strong defense to create an opening and then exploiting that opening will give you an edge over the other factions offensively. In terms of feats they tend to have an array of healing tools which can help beginners at least stall out enemies if they can't kill them themselves.

Knights
Knights are an all around faction. They don't do anything amazingly, but their stances are fairly balanced which gives them versatility to switch stances mid-combo and the ability to freely use the stances that put the other factions at disadvantage. Feats tend to be geared towards cooperative play and utility with AoE abilities as well as utility offense such as Flash Bombs.

Samurai
The Samurai typically have strong vertical stances in both speed and power, but their side stances tend to be significantly weaker and much slower. The Samurai tend to favor being hyper aggressive using quick strong vertical attacks combined with side feints to access vertical strikes that will actually connect rather than hit the block of the opponent. Feats tend to be geared towards offense.

Raider
The Raider is a heavy hitter, his Quick Attacks are still relatively slow, but his Heavy Attacks deal massive Damage for their slowness and large Stamina consumption. His Block is relatively easily Broken, but he does have a solid Health pool which makes him an all around character in terms of taking and dealing Damage. The Raider's Throws are some of the best in the game, whilst the Raider overall is considered a weak(er) character he does have an advantage in terms of controlling opponents which works in both PvP and PvE modes.

Gear
Throw > Revenge Mode Attack > Revenge Gain from Injury
Revenge Gain from Defense > Revenge Mode Defense > Feat Cooldown Reduction
Attack > Stamina Cost Reduction > Defense
Stamina Regen > Block Damage Resistance > Revive Speed
Sprint Speed > Block Damage > Execution Health Regen or Block Damage > Execution Health Regen > Sprint Speed
Exhaustion Recovery > Debuff Resistance > Revenge Mode Duration

As mentioned Raiders have some of the best throws in the game it only makes sense to increase it as much as possible so a successful throw can be used to control your opponent readily. Ideally you want to be Blocking or Parrying attacks not getting successfully Damaged so Revenge Gain from Injury is objectionably the worst stat you can boost aside from that further boosting your Attack can easily turn the tables when you're outnumbered in a matter of a few swings. Revenge Gain from Defense is pretty important as the Raider may have high Health, but he's slow making him a character that can seldom trade blows as most other characters' attacks will land first interrupting your own so it's best to wait for an opening to take advantage of his highly damaging attacks and thus you're going to want to be playing Defense until you can get an opening and Revenge Gain from Defense is the best way to survive situations in which you're outnumbered. Feat Cooldown Reduction and Revenge Mode Defense are about equal (with my preferred build), The Raider has a few strong passives that don't benefit at all from Feat Cooldown Reduction and your 4th Feat's cooldown is large regardless of your Feat Cooldown Reduction bonus while the lower feats should they be active are more reusable even with reduced Cooldown. Revenge Mode Defense is useful, but ideally you're not going to want to rely on Revenge Mode and it's clearly not active at all times so you may opt that it's not important especially when you consider a successful Parry while in Revenge Mode knocks enemies down leaving them vulnerable and with enough Attack on the Raider it can leave them dead or an inch from it and that's typically a better result than taking Damage. Attack is first and foremost to ensure every successful hit counts since you are on the slow side. In addition to being slow, the Raider drains Stamina extremely quickly so you need to ensure you can at least use your Heavy Combo without going into Exhaustion and if you decrease your Stamina Cost Reduction then you're going to have serious Stamina issues constantly so that leaves Defense as the odd man out unless you want to primarily stick to Light Attacks and at that point you're better off using a character more adept at chipping away at their opponent like the Warden. Stamina Regen ensures that you can recover your Stamina between your combos to continue dealing Damage on openings after Parries. Revive Speed has very little uses, it's often best to deal with enemies before trying to Revive so decreasing it has relatively little actual effect the majority of the time, when it does come into play is primarily Elimination where there are no Respawns. Dominion should be relatively close if your team isn't getting steamrolled and shut out and you can usually Rally with a coordinated effort should you go into Breaking before you absolutely need to get those Revives to stay competitive. Block Damage Resistance is one of the most important stats for Defensive characters as you want to be able to block both Light and Heavy Attacks to maintain your Health while you're Blocking, but it's also important for Glass Cannon type characters as you want to avoid taking direct Damage so you have to be ready to Block Heavy Attacks and you don't want to take that Chip Damage when a successful attack takes a massive chunk of Health off each time. Your Chest Armor is dependent on what mode your playing IMO. Sprint Speed is great for escaping combat which makes it very useful for modes where you're likely to get double teamed or simply need to traverse the map more like Dominion or even Skirmish. In Dominion you can recover Health easily by reaching a control point which compounds the uses of Sprint Speed and with Skirmish having Respawns the added Sprint Speed can let you reach your teammates so they can either aid you or you can aid them when they're in an unfair fight. In Elimination it's mostly 1 on 1 as even if you team starts to fall you start far enough away from each other that you have a little time to finish your current 1 on 1 fight and the added Health from an Execution can be the difference from dying in that second fight or be able to fight the next opponent without having to get to one of the limited Health Boosts. For any mode however Block Damage is consistently useful as the Raider primarily focuses on Throws and Heavy Attacks considering the Light Attack is only slightly faster to begin with that added Damage through a Block can save you a lot of Attacks which keeps it a middle of the road stat in all modes that use gear. Exhaustion tends to be death with it's numerous negative effects so recovering faster from Exhaustion helps solves that whether it's from your opponent draining your Stamina or from over-extending your own Attacks. Debuff Resistance helps with DoTs while this isn't extremely useful, having a shorter Revenge Mode actually can be a positive depending on how you use it. A short Revenge Mode allows you to refresh the added Shield which serves as a second Health bar meaning that if you use Revenge Mode while at low Health it offers more effective survivability than staying in Revenge Mode even one that's been heavily boosted and with Revenge Mode Defense which taking Revenge Mode Defense as a primary stat would reduce your ability to enter Revenge Mode to begin with.

Feat 1
Rush (Active) - Increase Movement Speed.
Tireless (Passive) - Lose Stamina at a lower rate.
Body Count (Passive) - Killing a Soldier restores Health and Stamina.

Tireless > Rush > Body Count

Rush is a decent starter it's good for Dominion, but pretty meh for Skirmish and Elimination. Movement Speed lets you cap zones quickly and escape in a pinch, but if you're always fleeing from a fight you're not contributing and you're hurting your own team and it offers no combat benefit like Tireless does. Body Count only works where there are Soldiers to kill, the added Health can be useful to a degree, but it's much easier to use a Health Boost or a Control Zone to restore Health even in Dominion where Soldiers are much more plentiful than Skirmish and the Stamina gained from killing a Soldier simply serves to lessen the Stamina loss even when hitting multiple Soldiers at a time. Tireless is essentially more Stamina which helps you directly in combat.

Feat 2
Marked for Death (Active) - Reveal Target Position and lower it's Attack and Defense
Inspire (Active) - Allies deal more Damage and Soldiers fight faster.
Bear Trap (Active) - Medium Damage Trap that stops it's victim from moving.

Bear Trap > Inspire > Marked for Death

Marked for Death offers you additional Damage and helps you stay alive while also sending out a beacon to your team about the whereabouts of an enemy, the major problem with it is that it requires a dual press activation than can let the enemy get a free Attack in depending on when you try to use it so it tends to be a Support skill that you activate on an enemy a teammate is engaged with so you can activate it safely and your team gets a benefit from it and typically for that purpose Inspire will be more useful especially in Dominion where you can fight near your Soldiers for free interrupts. Inspire can boost multiple teammates and unlike Marked for Death it can remain useful for multiple kills potentially, essentially it's a much better Support skill and since Marked for Death isn't terribly useful 1 on 1 due to it's activation Inspire tends to just plain be better especially in Dominion when fighting on the line with your Soldiers, but also on certain maps in Skirmish where fights can be clustered together. Bear Trap is very useful however it requires a decent while to place so it needs to be used before you actually need it or you can deploy it near a teammate that is fighting as it won't trigger on friendlies and an enemy in a fight might make a misstep that winds them up in your trap or if your ally is fighting at a choke point then you can seal off the enemies escape route, typically it works well in Dominion as you can set it up at a control point and use it to help siphon enemies to a different entrance less they're willing to purposely trigger the trap.

Feat 3
Second Wind (Active) - Recovers Health (limit 4 uses before long cooldown)
Fury (Active) - Sprint Speed increased slightly and Attack and Defense increased greatly
Battle Cry (Active) - Increase Ally Damage and make enemy Soldiers flee.

Fury > Second Wind > Battle Cry

Second Wind doesn't restore a lot of Health, but it can certainly be the difference between life and death particularly in Elimination Mode where the fights are minimal so those 4 uses last a lot longer since the recharge is massive after the 4 uses. While I don't personally use it, Fury is IMO the best option. Sprint Speed is helpful if you desperately need Healing, but taking out your opponent quickly and negating Damage helps you win individual fights so you can leisurely regain Health either from an Execution or simply not having anybody chasing you not to mention it's unlimited uses, but is on a cooldown so if you've chosen to ignore Feat Cooldown Reduction you might want to just opt with the safe option of Second Wind wish I prefer personally.

Feat 4
Fire Flask (Active) - Projectile for Medium damage creating a Fire Area of Effect that lights enemies on Fire.
Stalwart Banner (Active) - Deploys an Area of Effect Healing Aura at the target it was activated on for you and your allies.
Slippery (Active) - Auto Block Grab attempts for the Duration.

Fire Flask = Stalwart Banner > Slippery

Fire Flask is useful for a few things the first being causing grouped enemies to scatter as standing in the flames is fairly damaging. It can also be used to clear out a mass amount of Soldiers for a large boost to permanent points in Dominion or even help you claim the Battlefield front in more or less a single attack even if the enemy undisputedly had it, you can use it to temporarily close a choke point as most people won't attempt to run through the flames even if they have the life to do so, and finally the direct Damage it actually deals is moderate so it can outright kill enemies it explodes on. Stalwart Banner is all about healing, it has a long cooldown so I'd only consider it viable if you're boosting Feat Cooldown Reduction, but Healing is always useful and it's Area of Effect for allies so that's a free added bonus. It has less impact on Dominion where it's much easier to regain Health at a friendly Control Point, but it's still useful. Slippery is helpful primarily in 1v1 situations which means Elimination matches, but being that you have to unlock it, it's only available late game unless you've had to pick up the slack for you team in Elimination in the early rounds so it sees very marginal use overall.

Warlord
The Warlord is a duelist type character in that he finds his niche in fighting one on one otherwise he has issues with low reach, narrow swings, and little combo ability he simply can't manage to Damage two opponents at the same time very well. With his total block and guard that is hard to break he can however stall effectively and gain large amounts of Revenge especially with increased Revenge Gain from Defense coupled with a number of defensive Feats he can be rather hard to kill when outnumbered even if the Damage he can return is limited he certainly is a character apt for waiting for reinforcements.

Gear
Revenge Mode Attack > Throw > Revenge Gain from Injury
Revenge Gain from Defense > Revenge Mode Defense > Feat Cooldown Reduction
Stamina Cost Reduction > Defense = Attack
Stamina Regen > Block Damage Resistance > Revive Speed
Block Damage > Sprint Speed > Execution Health Regen
Revenge Mode Duration > Exhaustion Recovery > Debuff Resistance

The Warlord likes to whittle away at the opponents Health rather than dealing large quantities of Damage with each attack which means you're going to want to be able to toss your opponent around fairly well for those surprise ledge kills with your unblockable running Shield Bash which is both quick and efficacious in supporting an ally, but it shouldn't be your primary concern either as Throws are more the Raider's shtick. Revenge Mode Attack with the Warlord's ability to gain Revenge using the total block is going to help you cover your large weakness of not being able to deal Damage in an outnumbered scenario so instead of just stalling you can actually win a few of those scenarios yourself without too much extra stress. Ideally you want to make sure you're blocking and with your total block that shouldn't be an issue so Revenge Gain from Injury is even lower priority on the Warlord than most. Revenge Gain from Defense is the Warlord's bread and butter. While it is useful on all characters the Warlord is a Defensive style character centered around his shield, not only does he have that total block for outnumbered scenarios he can also block using his Heavy Attack if you time it correctly which means you not only deal Damage, but you gain Revenge as if you blocked their Attack as well. As a secondary stat a lot of the Warlord's best feats are Passives which makes him not only a low fuss character, but means he can safely ignore Feat Cooldown Reduction depending on the build and while Revenge Mode Defense isn't terribly great, it's a nice bonus to have as well when you're already a Defense minded character. Since your goal is to whittle away at your opponent the priority is to be able to launch attacks with impunity not to mention your total block consumes a fair amount of Stamina as well so reducing the Stamina Cost of you actions is likely where you're going to find your large benefit. Attack and Defense are both important stats depending on how well you do Blocking you might want to supplement your Defense and decrease Attack instead doubling down on the stalling type support role, but if you Block well then Attack as a secondary stat will make you more self-sufficient. Stamina Regen supports your ability to chip away at the enemy fueling your quick jabs and your Defense against multiple enemies without going into the Exhausted state. Block Damage Resistance keeps your Defensive playstyle from coming back onto you as a negative helping to absorb Damage through your Block which some of the stronger characters tend to throw quick a few Heavy Attacks to get the Damage they need to make up for their lack of speed. Revive Speed can be safely ignored unless you want to be a full support role then maxing it and taking the Quick Revive Feat will let you Revive with impunity. Being that you're a stall character you with lots of healing you don't particularly need to run away which lowers the priority of Sprint Speed so you can safely take Block Damage which further plays off your chip playstyle so if you miss your opening and hit their Block you can still deal Damage. Execution Health Regen is low priority as you have several Health centric Feats, but like most others you can can sub out Sprint Speed in Elimination Mode. Debuff Resistance is pretty low priority though DoTs and Feats do go through your character's Defense so bear that in mind. Exhaustion Recovery shouldn't come into play as much when you're focused on Stamina Regen and Stamina Cost Reduction so you might as well prioritize Revenge Duration when you have a largely buffed Revenge Mode with the rest of the build.