How to create a combo chain instructions. (Downloading Sword Mastery https://www.nexusmods.com/eldenring/mods/1890 is not necessary but HIGHLY recommended, both as a mod to complete setup for your regulation.bin and as a reference, due to Sword Mastery being the most advanced combo system in Elden Ring modding as of 2022.)

Go to your regulation.bin's SpEffectParam and find rows 1681 and 1683, modify their duration to be 0.1 and their physical damage from 1.075 to 1. Do the same for rows 1811 and 1813. (For those who wish to preserve these spEffects, you'll need to duplicate them before modifying and add a prefix to them, like 621, so you have spEffects 6211680, 6211681, and make sure 6211680 chains into 6211681, do the same for the others. Then modify TAEs 740 and 741, replacing any effect with the replacement effect, so replace AddSpEffect_WeaponArts 1680 in s32 SpEffectID_EnoughFP with 6211680) Those are Barbaric Roar and War Cry spEffects, respectively.

Key:

aXXX_XXX500 is DCharge1
aXXX_XXX501 is DShift1
aXXX_XXX505 is DTapped1
aXXX_XXX510 is DCharge2
aXXX_XXX515 is DTapped2

aXXX_XXX600 is BRCharge1
aXXX_XXX601 is BRShift1
aXXX_XXX605 is BRTapped1
aXXX_XXX610 is BRCharge2
aXXX_XXX615 is BRTapped2

aXXX_XXX620 is WCCharge1
aXXX_XXX621 is WCShift1
aXXX_XXX625 is WCTapped1
aXXX_XXX630 is WCCharge2
aXXX_XXX635 is WCTapped2

War Cry changes your heavy attacks from aXXX_XXX500 to aXXX_XXX620, and Barbaric Roar changes your heavy attacks to aXXX_XXX600. Blending special heavy attacks, such as putting speffect 1810 in aXXX_XXX600 will not result in a smooth blend, as your character will take 1 frame to A-pose as the hks file does not know what to do in this situation, before moving to your designated special attack. This phenomenon doesn't seem to occur when going from normal heavies to special heavies, and vice versa.

SpEffects can govern what kind of animation comes out. By default, on the first and third light attacks, the odd numbered attacks, after performing one and immediately going into a heavy attack, aXXX_XXX501, 601, or 621 is played. You can force this to happen if you have SpEffect 133 on when you are doing the heavy. To skip this '01 animation, then make sure your character has SpEffect 134 on when you are doing the heavy. Shift animations will always go to the corresponding Charge animation, provided that you are not stagger. This happens either right when an InvokeEventEsStateFlag<HKS_env301> event occurs or the animation naturally finishes. A strange interaction occurs when you put SpEffect 134 inside a '01 animation, where once the SpEffect kicks in, your character does the '05 animation (Further testing needed).

The progression of heavy attacks goes like this:

Shift (depending on whether SpEffect 133 or 134 is active)
v
Charge1 -> Tap1 (depending on whether or not your heavy attack button is pressed when SpEffect 100280 is active)
v
Charge 2 -> Tap2 (depending on whether or not your heavy attack button is pressed when SpEffect 100280 is active)

SpEffect 100280 governs whether you should transition to a tapped heavy animation. As long as the SpEffect is on, if you release the heavy attack button, you will transition into the tapped heavy animation.

SetBool 32_0x7C_7_hks271 causes your character to believe that it is back at the beginning of the attack loop. This event can be used to shorten combos, such as by putting it right before the Cancel - RH Attack event on the third attack, so that the fourth attack never happens. This is also useful if you have a default heavy attack on either Charged1 or Tapped1, as adding the War Cry effect to go into the War Cry heavies will transition you to WCCharged2, but if you put SetBool 32_0x7C_7_hks271 before the Cancel - RH Attack or InvokeAnimCancelEnd_R2_HeavyKick then you will transition from DCharged1 to WCCharged1.

Knowledge of where the animations are is pretty important. You should know the following: aXXX_030XXX is for right 1H attacks, aXXX_031XXX is right 1H aerial attacks and recovery, aXXX_032XXX is 2H attacks, aXXX_033XXX is 2H aerial attacks and recovery, aXXX_034XXX is for powerstanced attacks, aXXX_0345XX is for powerstanced aerial attacks and recovery, aXXX_035XXX is for left hand attacks, a038XXX is right side horse attacks, a 039XXX is left side horse attacks.

Combo Chain Tips

Blend is your friend. The Blend event allows one to blend animations together, so that animations are smooth and connected. If your animation has weird feet twitching, weapon twitching, or any other strange things going on, you may have underblended or overblended. You can view the blend between two animations by hitting Spacebar on the first animation, then when you want to transition to the next animation, click the next while the current animation is still playing. The previous animation's number should be grey and the current animation's number should be yellow.

If you are having a hard time blending feet, then you should try attaching SpEffects 100130 (this desyncs your character's legs from his body, and makes the legs a crouch with the left foot forwards and both feet facing the right (Square Off stance)) or 100150 (this desyncs your character's legs from his body, and makes the legs a crouch with the right foot forwards and both feet facing the left (Unsheathe stance)).

To prevent accidental imbalances, if you import an aXXX_XXX505 to work as a combo branch attack, make sure to change the s32 BehaviorJudgeId in InvokeAttackBehavior to something like 200, 800, or 0, instead of 300. If you imported from an aXXX_034XXX, then change your s32 AttackIndex, s32 BehaviorJudgeID, and u8 Source accordingly, so as not go get an attack from your left hand have its hitbox in your right.

In the case of your attack not having sound, check your regulation.bin. In EquipParamWeapon, there is a category in each weapon called Weapon SE ID Offset. Some weapon movesets are built around a certain Weapon SE ID Offset number, like Greathammers. If you notice a sound missing, check out the animation you got it from, which weapon it belongs to, and see which Weapon SE ID Offset Number it has. Alternatively, you can just copy the sound events from a previous attack with sound and shuffle it around to align with the new attack's sound events.

For combo chains that force you into the air, it is good to use InvokeIsLadder, Disable Gravity, and Jumptable 51 (prevents you from defaulting to the falling animation). SpEffect 100630 forces your heavy attack to become the aerial heavy.

Jumptable 24 gives you unbreakable poise.

The HKS that governs combo chains requires exact row IDs, meaning that it's not about the contents of the spEffect's character but the row ID it was born in (sorry MLK).

Damage Level determines level of bounce off. The FEXTRALIFE hardness tiers of 4 hardness tiers is correct in vanilla, but that's because FROM only uses the four values. It is actually a gradient 0-255 (that you can set, real value has maximum of around 500-600ish) for hardness value. If your weapon's flick (repel) power is lower than the flick (repel) defense of whatever you are attacking, you get certain bouncing animations, 3X9X0. Damage Level 2 causes you to bounce off in a 3X910 bounce animation depending on which hand's weapon hit the target (determined by behavior params but also by invokeAttack TAE). Damage Level 4 causes you to bounce off in a 3X920 bounch animation.

Dummypoly 180 is a natural reverse grip dummypoly for the right hand that you can use in EquipWepAbsorbosParam.