Inventor's starting item is gun.
Gun's average damage is 50.
He can craft genedaz.
Genedaz made from 1 tinder and 2 flints, it's cheap.
3 was made.
Average damage for each is: 60
Gas made from 1 spider / snake 's venom.
Spider gas is the most weak kind of gas and it's damage is nearly 100.
Troll's starting average HP was 200.
Gun + Genedaz + Gas = 50 + 100 + 60= 210 !!! 210 > 200
Use Shift and click them on the enemy Troll.
Then, one will die.