To unlock the third level, Misty Mountains, in Multiplayer collect all 8 artifacts found in the game.
Unlock Gimli in Multiplayer
To unlock Gimli in Multiplayer beat the game with two characters on any difficulty, then in multiplayer select an empty slot and choose Gimli as your character.
Weapon Power-up
If you hold down the "B" button your weapon will start sparkling. With a sword it will kill a Goblin or an Orc in one hit.
Clone Items and People
Drop an item and save the game. Select continue at the main menu and there will be 2 of the item/person (not including Characters).
Hint: Duplicating items in multi-player mode
Trade an item from character one to char two saves and have both turn off the game. Both characters should now have the item.
Hint: Easy spirit
Find a place where Orcs, Trolls, Wargs, young Wargs, or Goblins cannot get you. For example, in the stone fence above the health pool when you are against the Fargon Troll (only the little Troll can get you). Then, stand still for about six to ten seconds.
Hint: Easy levels and gems
If you are having too much difficulty passing a level, wait until you are about to die then save your game and quit. Restart that game and you will start back at the beginning with full health, full spirit, the experience you just gained, and all enemies are re-spawned for you to kill again. Repeat this several times to gain easy level ups, gems for buying power-ups and items, and to rack up kills in order to reach the 500 point skill increases.
Hint: Moria: Easy Orc kills
At the beginning in the mazes of Moria, Orcs scream and run towards you on another side of the wall. You can kill them through the wall.
Hint: Artifact locations
Bilbo's Map (Aragon, Frodo, Legolas)
Found in a Dimril Dale map. An elf will ask you to recover a lost item from some Orcs. Two Orcs will be guarding a chest and one of them will drop the artifact when you kill it.
Narsil, the Sword of Isildur (Aragorn, Legolas)
Found in Lothlorien at the bottom of the map. It can also be found by Frodo in Crinfanti.
Chain Link of Morgul (Aragorn, Legolas)
Found near the end of a Rohan map called the "East Wall". You start the level between three bushes (one big on the right and two smaller ones on the left). A bright blue Troll will appear and start running away. It invincible, but you can follow it to a cave. The chainmail will appear there.
Sauron's Ashes (Aragorn, Gandalf, Legolas, Frodo)
This is found in a tower at Helm's Deep up a large flight of stairs in the "Gorge" level to the north. It is the map immediately after you defend the broken wall with Gimli. A chest will appear to the left of the forge after opening all the boxes and chests on the northeast wall. Frodo does not go to Helm's Deep, but he can find the Ashes in a Mordor or Emyn Muil map.
Moria's Lamp (Legolas)
In the map where Legolas, Aragorn, and Gimli meet Gandalf, Moria's Lamp is hidden in a secret area at the top of the map. You have take a path to the right of the screen and group, then left. When you walk into the edge of the screen, you will disappear to another area where you can easily get the lamp.
Balin's Book (Gandalf)
This is found in Balin's Tomb before the Cave Troll enters, just below the actual tomb.
Troll Tusk (Frodo)
Found in Moria (just after the bridge of Kaza-dum). The Troll Tusk can be found in the northeast corner.
Judkins Scrolls (Eowyn)
In one map, a woman will ask you to clear town hall (a large building in the center of the area). Instead of immediately going in, go near it, then wander around the level for awhile, killing things and collecting items. When you return (usually), you can find the artifact in front of a wood pile to the west of the town hall door.
Killed/Faking Orcs
If you have killed an orc, it will fall forwards, if it is faking death it will fall backwards. You can also tell if the orc leaves an object on the ground that he is dead, but not all dead orcs leave items, so that is not as reliable.
Glitch: Power Legolas
To make this glitch work you need Legolas and the magic move,Overdraw.Once you have got that you hold down B so your Bow sparkels,then hold down A[with Overdraw as the magic move your using].Then let go of B,as soon as you have let go of B let go of A and watch the power rings grow.You can now walk around with the rings still with you.Sadly it doesent make your shots any more power and once you use Overdraw again,the rings dissapear.[If you meditate when you have the rings around you they go a weard colour]