I searched around on several sites and haven't been able to find an answer to this. Since I like knowing the actual numbers behind things, not just vague descriptions I've been wondering: by how much does warcry increase attack? Also, does it have any other effects such as morale or defence or even attack speed?

No hard and fast numbers.
I work on the basis that its a bonus for attack in melee and a small morale boost.
In any hand to hand combat situation if you dont warcry you have missed an opportunity to improve your odds.
One exception..hidden troops. Will warcry give away the morale bonus you get from being hidden and prevent the surprise effect on the enemy morale? Shrug.dont know. If I have two hidden I will warcry one and surprise with the other.

+10(!) attack for thirty seconds. Apparently this is hardcoded and unchangeable (should you have wished to).

Bastarnae + warcry = human meat mincing machine.

what you kidding me? legions can hold a barnastae warcry just.

you know, Severous, you COULD surprise with both and then use the Warcry once you start attacking..

No because once your forces are engaged, you can't warcry.

Not true. The button becomes active from time to time, and if you manage to click it, you get another warcry.

I guess it must be when a certain number of them is engaged or something.

+10 attack on the war cry? Wow! No wonder my chosen axemen have been hacking their way through anything in front of them. So if war cry gives you +10, any idea what 'combat bonuses' give? Such as skirmishers being better against chariots and elephants, or spearmen against cavalry. How much better are they against these units than any others?

Yeah, I also wonder about that.
Also the things such as 'combat bonus in X terrain type' btw- does combat bonus in snow just mean snow on the ground, or snow has to be falling?
And what does expert at hiding in woods do? I thought you could either hide or not hide. What's the difference?

hEY I WANTED TO ASK HOW DO YOU DOWNLOAD UPDATES OF ROME TOTOAL WAR

hEY I WANTED TO ASK HOW DO YOU DOWNLOAD UPDATES OF ROME TOTOAL WAR

1. This is not the place to ask this kind of questions. The FAQ is a better option.
2. You can get the patches from the official Total War website. If you have version 1.0, install the 1.3 patch first, and then install the 1.5 patch. To check your version, go to the options screen. Your version number is displayed at the top-right of the screen.
3. Put off CapsLock. It makes your posts easier to read.