Followup from my last comment, it appears the 20% is hard coded into a passive granted on wielding a hexblade:
As long as you have a Pact of the Blade Weapon summoned, the status "HEXBLADE_BIND" will be active on your character along with the hidden passive "HexWarriorTechnical":new entry "HexWarriorTechnical"
type "PassiveData"
data "Properties" "IsHidden"
data "StatsFunctorContext" "OnAttack"
data "Conditions" "HasStatus('HEXBLADE_BIND', GetAttackWeapon(context.Source)) and not HasStatus('HEXBLADES_CURSE',context.Target) and IsWeaponAttack() and not IsMiss() and (Character() and not Dead()) and RollDieAgainstDC(DiceType.d20,17);"
data "StatsFunctors" "TARGET:ApplyStatus(HEXBLADES_CURSE,100,10)"
Attack and connect with one of these summoned weapons against a living character the game will roll a unique D20. If you get equal to or greater than 17 on that die it applies the curse "HEXBLADE_BIND" to your target.
In theory, we could boost the die like we do with all others but it doesn't appear to be named here. I'll try some boost codes and see if anything connects.
So as of right now, the only 100% chance of applying the curse is with the spell or a modded version of the passive granting 100%. These values might be beyond the reach of a cheat table but not the BG3 modders toolkit.
How to use this cheat table?
- Install Cheat Engine
- Double-click the .CT file in order to open it.
- Click the PC icon in Cheat Engine in order to select the game process.
- Keep the list.
- Activate the trainer options by checking boxes or setting values from 0 to 1