2 quick RTW questions:

[Craterus]

I don't know what the bonus is, but it's likely to add to attack, and possibly charge.

[gardibolt]

If you have 2 units that have the warcry ability, and one is in combat, will it get a bonus if the other one does a warcry? Or does that bonus apply only to that particular unit?

Anyone know how long the warcry effect lasts?

[Craterus]

I think the attack bonuses apply to the single unit. But there could be a morale bonus for surrounding units.

Warcry lasts about 40 seconds, I think (don't quote me).

[Uesugi Kenshin]

Weapons with armor piercing on them halve the victim's armor rating, it is explaibned at the top of the export_descr_unit file iirc.