Fire Throwers are recruited from the Mercenary Post for 100 gold each, making them the most expensive Arabian unit. The fire thrower is a unique ranged troop, using grenades of Greek fire set surrounding ground, buildings, and troops alight.
Fire Throwers are very slow, have a very short range, low rate of fire, and little health. However, they can light Pitch Ditches on fire without Braziers, and they can start a fire anywhere and keep it going indefinitely. Certain landscape features (notably bushy shrubs) can be set alight, although their number is not usually great enough or in a place that can be manipulated in a defensive or offensive manner.
Tactics
Fire throwers require good castle and economy lay out in order to be effective defensive troops. Their potent flames and unpredictable firing can easily destroy your castle from the inside if not properly controlled.
A common mistake is placing fire throwers on top of the keep. While this can be effective in times of hardship, if you have a stable economy surrounding it, they are better not used.
Fire throwers are too slow, short ranged and weak to be of any use in an offensive manner (such as the portion of an army), especially considering they may light YOUR troops. Control your defense by creating separated layers of wall overlooked by Lookout Towers, allows Fire throwers the tight, closed spaces they require to burn large numbers of attacking troops.
Since Fire Throwers are able to light pitch ditches on fire they can be used to light enemy pitch ditches on fire burning their enemies troops but they need to be protected.