Set the target
Enter enemy health plus armor as one number. Armor matters because exact lethal must beat the full total.
Free tool
Hearthstone lethal calculator
This public tool can rank before the plugin is mature. It explains the product in one minute and teaches beginners how to count visible damage.
Result
Lethal available: 17 / 18Route will appear here.
How to use it
Count damage in the same order every turn.
Add visible damage
Split board attacks, hand damage, weapon swings, hero powers, and spell damage so you can see which bucket is carrying the route.
Apply blockers
Use the taunt checkbox when board attacks cannot go face. For complex boards, subtract the clear damage first, then re-check the remaining face damage.
Common missed lethal causes
Most missed lethal turns are not caused by one huge combo. They come from small leaks: forgetting hero power, counting a taunted minion as face damage, playing spell damage too late, or spending mana in the wrong order.