No named variable for dueling bonus, you can use =if(StartAttacksAttack1Dueling<>"",2,0)
The actual logic is a little more complicated =IF(AND(FightingStyleDueling=1,StartAttacksAttack1Dueling="•",OR(Attack1group="Simple Melee",Attack1group="Martial Melee"),Tables!ABB59=""),2,0)
Tables!ABB59...