Defeat Gorthmog
To defeat Gorthmog the Orc Army Commander, you should have these abilities (or better) and items: Morgul Decay, Dispel, Gift of Galadriel, Citidel Rage/Ecthelion Wrath, crippling moves, and Arnor Mushrooms.

First, use Morgul Decay on Gorthmog. Now his armor is zero. If you kill one of Gorthmog's minions, he uses Black Gate to bring them back. Use crippling moves to keep them out of battle. If Gorthmog's minions use Mordor Mirror, use Dispel to get rid of it. Gift of Galadriel will help with healing Faramir, since he has powerful attacks and tons of health. Use Arnor Mushrooms on Berethor if he has Citidel Rage or Ecthelion Wrath so his moves are powerful. After Gorthmog goes chicken and runs away, finish off his followers and then you win the battle! (Perfect Mode really helps in the battle.)

Berethor: Good sword:
To start the the game with a very good sword for Berethor (the first character you start with), do the evil mode of Osgiliath and save it on an early game. By doing this, you will get the Sword Of Isildur, which has a 200+ damage rating. At the beginning of the game, you can give at least 2,000 damage points from a normal hit with this weapon.

Morwen: Better weapons:
Use her Steal Item ability on unique enemies (i.e. Bosses) such as Grima Wormtounge. This will give you weapons not found anywhere else. Note: Some of the Bosses have the same weapons.

Morwen: Ultimate weapon:
Use Steal Item from the Witch King at Pelennor Fields to get the Third Age Rohirric Silver Battle Ax (base: x90 +9 per level, +8 Str, -2 Dex, +3 Spd).

Building skills:
Get some of the best skills very early in the game, just practice. In the first level, find an enemy respawn point near a save point. Once there, keep attacking until you run out of AP and save the game. Your AP should have refilled, as well as your health. Keep doing this, and after a few hours you will get the special move from Berethor that can hit an enemy five times in a row. Note: This works for all characters, and not just Berethor.

Evil mode:
Complete a chapter to unlock the ability to replay it in Evil mode. This is an easy way to gain weapons, armor, and Elfstones.

Restore HP and AP:
If you are low on HP or AP, find a save point. Save your game and both your HP and AP will be completely refilled.

Everlasting health:
Once your Elf healer gains the Valor move that presets whoever you choose with an instant revival when ever you die, use it at the beginning of each battle on her first, then on everyone else. If you maintain this so that no enemies can truly kill you, you will almost always be the victor.

Better healing:
If you use Elf Medicine, try and use it with Idrial. If this is done, it will give full health instead of half.

Fight the Balrog:
Stock up on Elf Medicine before fighting the Balrog. Have Gandalf use it to bring you back to life; you will get more unit points back if Gandalf uses it on you. Also, equip any Fire protection Elf Stones you have. The Balrog has about 70,000 HP.

Use the following trick to defeat the Balrog or Witch King. You must have first opened at least 25% of the treasure chests before the Balrog. Save just before the Balrog or Witch King. Then, check for two items in your inventory, Arnor Mushrooms and Morgul Decay. If you have at least one of these, it will be an easy battle. When you start the battle, have Gandalf use Protection From shadow. Then with the rest of your characters, use Morgul Decay on the enemy to get rid of their armor and use Arnor Mushrooms on Gandalf. Note: If Berethor has a weapon with 150+ and has double attack and Ecthelion Wrath or better, use Arnor Mushrooms on him and he will do a lot more damage. Take out Idrial and use Heal on party until all are dead except for the main attacker. After a while your opponent will be dead.

When fighting the Balorg. use a Morgul Decay, which will make its armor 0. Once that is done, you will do about ten times more damage and defeating it will be a lot easier.

Fight the Mumakil:
Use Stand Fast to prevent stun from Stomp; Paralyze to prevent Melee; Silence to Stop Spirit Immune to Bind Ranged; so Blind and/or Reduce Ranged Damage from Haradrim Volley (only attack it has remaining). Pierce is also recommended.

Fight Sauron:
On the battle of The Dark Lord Sauron, use Morgul Decay just like was done on the Witch King. The Dark Lord knows Berethor is strong. He will probably use Darkest Fear on him, then he will not be able to battle for a while. Use Elven Rage and it will do somewhere from 16,000 to 19,000 damage if it is a critical hit. Do not use Elegost. He misses often when you fight the Dark Lord. Try Eaoden, but his move Drain Health still only does 4,000 HP. Use Hadhod and kept using Cleaving Wound.

Have Hadhod, Elgost, and Berethor in your party. Make sure your Perfect meter is full, and you have Hadhod's passive skill that lets him always get criticals when the Perfect meter is full. On your first turn, use Morgul Decay on Sauron. On Berethor's first turn, have him use either double attack with Company Migh and War Call, or Company Night if you do not have Double Attack. Next, add the item that adds light damage to your melee/ranged attacks to Hadhod. He should now do about 33,000 damage every time he attacks.

Fight the Witch King:
To defeat the Witch King at the Pelennor Fields, make sure that you have Hadhod's Second Age Dwarven Mithril Piercing Axe and the Dwarven Mithril Helm. When you face the Witch King, use these attacks: Berethor's Stunning Strike and Ectehlion Wrath, Hadhod's Mountain Rage, and Eaoden's Enraging Blow and Rohirrim Rage. The Witch King has 200,562 HP and 59,098 AP.

Enter the fight with Perfect mode. Have your first character use the Banner of Elendil special. It will not actually stun the Witchking to make him stop attacking, but will disable his ability to counterattack for a great while. Then, have your next character use Morgul Decay, an item that completely rids the enemy of its armor. Now that the Witchking is completely vulnerable and will not counterattack, have your characters deal out their combos, such as Berethor's Ecthelion Wrath and the Rohirrim's Wrath of Edoras.

Fight Orc Veterans:
In the Minas Tirith and Pelennor Fields levels, your basic Orc Veteran has at least 20,000 HP. You can use Berethor's Orc Bane twice to kill them. If it does not die, just use a plain attack to save your AP.

In Osgilath, you will encounter the big Orc featured in Lord Of The Rings: The Return Of The King. First, use Farimir's Quality (where he will counter attack for someone). Do it to everybody. He will counter attack for everyone with a volley of arrows. Then, use Captain's Volley until he runs away. For Berethor, use Ecthelion Wrath. For Idrial, use Loud Water Fury. For Eadon, use Rupture Armor. You may also want to use Morgul Decay. Do not have Elgost out, as he misses to much. It is best to have Idrial, Eadon, Berothor, or Morwen.

Helm's Deep:
When you are at Helm's Deep, find Gamling in the armory. He will tell you to find Aragorn and his friends. Legolas will tell you where Aragorn and Gimli are located if you find him first. Legolas is outside along the wall. You must also find King Theoden who is also outside. After you talk to all of them, you must go back to Gamling. He will tell you that the Orcs broke through and it is time to fight. You will get to fight with Legolas first, Gimli next, then Aragorn last.

Transferring Evil Mode treasure:
Any treasure acquired in Evil Mode can be transferred to a regular saved game.