Article in progress: explanation of the FGO Damage Formula:
-Terms or variables in the formula
-When they are applicable
-How they apply in practical usage
In the meantime, for those who stumbled across this page, please take a look at the Beast's Lair forums for a useful reference!
LINK
damage for this card = [servantAtk * npDamageMultiplier * (firstCardBonus + (cardDamageValue * (1 + cardMod))) * classAtkBonus * triangleModifier * attributeModifier * randomModifier * 0.23 * (1 + atkMod - defMod) * criticalModifier * extraCardModifier * (1 - specialDefMod) * {1 + powerMod + selfDamageMod + (critDamageMod * isCrit) + (npDamageMod * isNP)} * {1 + ((superEffectiveModifier - 1) * isSuperEffective)}] + dmgPlusAdd + selfDmgCutAdd + (servantAtk * busterChainMod)