The Lord Of The Rings: Tactics Codes -

Black Gate/Mt. Doom
It is a good idea to have Stealth Of The Shire 1 and Courage Of Sam 3 to get past the enemies. If you use it, you will block all attacks on Frodo and Sam. Note: This is the last level of the game; it does not work in multi-player mode.

Host Of Mordor
When playing as Host Of Mordor, always do the extras with Sauron and The Witch-King to increase their stats for the last level.