How do you use hydras?
 

One of my provinces can produce hydras, so I produced a bunch of these guys.

But no matter what I do, they seem to do more damage to me than the bad guys.

Any ideas on how to use these guys?

Re: How do you use hydras?
 

Use Poison resistant troops, like undead, with them. Your commanders should be PR at a minimum, you can do this through items. Or make sure your units are really far away from them, but they'll probably mix in a long battle no matter where you put them. Or don't use anything with the hydras, set them on the far right of the map, and to retreat, they'll leave a big poison cloud everywhere that your enemies will chase them through.

ETA: One fun spell that looks like it will do well with Hydras, and Bog Beasts, is Moss Body. There'll be a lot of poison floating around if you're buffing with that spell.

Biiiiiig gap between hydras and non-chaff.
 

And different orders as well -- the hydras should be good to go immediately and attack rear or archers, while the non-chaff units are further back with hold/attack. Even then there will be friendly-fire casualties without a full poison-immune force.

I used perhaps an even dozen in my first game as Sauromatia. Kept them on a flank, relied heavily on archers (both national and banefire) and somewhat less on normal melee troops.

Re: Biiiiiig gap between hydras and non-chaff.
 

Hydras will poison anything near them, so if you don't have a poison immune force, you have to use the hydras by themselves. Hydras regenerate, so you can use them alone vs. independents very easily, especially if you combine them with a priest that can cast fanaticism (so he can stand way back), or that has a poison resistance item. But, the indy hydras are small and weak compared to Sauromatia's, and don't hold up as well.

Hydras are frankly very awkward and difficult to use. I don't really recommend them, most of the time.

Re: Biiiiiig gap between hydras and non-chaff.
 

After some efforts, I decided only to use them as part of a 100% poison-immune force. Normally I use them as part of an all-hydra strike force. They're unusual in being a fairly strong unit worthy of the late game (due to the regen) recruitable as an ordinary (if capital-only) unit.