In the level, Anduin River; Campsite, go through the covered bridge and strait to the experience pool. Touch it to get the experience. Then save the game and turn it off. Load the game and go back to the pool, it will now be a health pool.
Witch King's Crown
To aquire the artifact, Witch King's Crown, beat both the Witch King and his flying mount with Eowyn. After you kill them, walk back to where he began by talking to you. The artifact, Witch King's Crown, will be laying on the ground.
Feather of Gwaihir
To aquire the artifact, Feather of Gwaihir, battle Gandalf up to the point where he can use the ability, Summon Gwaihir. Use the ability, and the eagle will swoop, dropping a feather. Gandalf will aquire the artifact, Feather of Gwaihir.
After Frodo is injured by Shelob you will begin to play with Sam. Defeat Shelob, and you will aquire the artifact: Shelob's Stinger.
After entering the level, Ithilien North, go up and then right along the path. You will walk under a large waterfall, go up. You will enter a secret level where you can go to a forge, ranger hollow, or aquire a rune from a man standing by a building.
While fighting through any stage, you will (naturally) accumulate experience. To double (or re-double) your EXP gain, simply let your hero expire before the stage is over and you are forced to restart the stage.
The EXP gained previously is kept, but the chance to play through the stage again to get more experience for higher levels is available.
This trick can be used with Gimli, Aragorn, or Eowyn. First, make sure you have a shield and a two handed weapon equipped. Keep swiching them out and every time you switch them the damage you do will increase(look at the attribute screen to see how much damage you do). The damage you deal will eventualy go back to normal but you can repeat the trick as much as you want.
In multiplayer, trade the item you want to copy to the other player. The player who receives the item saves his game and the one who gave the item does not. The giver reloads his character and will still have the item and so will his friend.
To unlock Sam, use the link cable to connect to the GameCube (while the LOTR: Return of the King game is in the Cube). Sam will be unlocked for multiplayer.
There and Back Again
In the level, Corsair Camp, go up and right untill you come to a woman near the top of the screen. She will ask you to bring her brother back to her. Walk down and a little right down steps and cross the river. Walk upwards untill you come to her brother, then walk back to her. She will thank you. Now walk back near where you entered the level, the woman will be standing by a tree. Kill the corsairs around her and go back. She will open the door to the covered bridge and you can go through. Talk to her brother, he will say that he hid his adventure book but cannot remember where. Break open the barrel in the corner down to the right. You will find the artifact There and Back Again.
If you are having trouble getting a character past a certain point, go into a bonus map with them. You can get lots of experience and purchase items like runes, skill points, or kingsfoil erbs. Bonus maps can be just the boost you need.
Witch King Help
When you are fighting the Witch King with Eowyn, lead him near a flame. Cross it quickly, and then stop, so that he follows and stops on top of the flame. Keep hitting him without moving and he will go down very quickly and will not be able to recharge before he is dead.
In the upper-most level of the tower of orthanc, where you fight Saruman, go down to where you speak to him, and then go North-East to a flight of stairs at the top of the screen. Go up the stairs and to the left. There will be a chest, open it and the artifact, Saruman's Palantir, will fall out. Do not defeat Saruman until you have done this or you will not be able to go back.
In the bonus map, Fangorn Forest, the first level contains a portal. Go north-east almost up to the end of the level where your pointer will register red. Turn left and walk up to a space in the grass with a tree stump next to it. Stand next to the space and you will be transpoted back near the begining. You can go back and forth between these two and orcs and goblins will reapear every time, making for easy experience.
Bonus Map: Fangorn Forest
After you have played all the way through the game with all six regular characters you will unlock the bonus map, Fangorn Forest.
In the level, Hidden Path in the White Mountains with Gandalf, walk around the level killing things. When you reach the uppermost path where your pointer points straight right, go left, break open the barrels, and walk around the ledge. Then backtrack back to near where you started the level. On the path going across above where you started above a waterfall there will now be a cave. Go in and you will be in a secret spot with a Ranger Hollow and a troll, along with drummers, crebain, and barrels.
Follow the Rats
In the level, Dark Paths, in the Paths of the Dead, near the begining of the level, you will see a group of rats running together, follow them. They will take you through the shortest path through the level.
In the level after you save Frodo with Sam, walk up the stairs and left. Walk all the way to the end and then down and back right as far out as possible. On a platform will sit a rune.
Last Level Boss
With Legolas, Gimli, and Aragorn, at the last level when fighting the servant of Sauron at the Black Gate, close the lever on one side, but not the other. The first one you close will stay shut, but the second will burst open along with the first. Then fight out one side and run in and kill the gaurds, then the boss.
With Eowyn on the level, River Crossing, cross the river. The camera shows a horde of orcs. The artifact, Simbelmyne, will be below a pond in the valley where the orcs are.
In the level, Ithilien North, near the end of the level you will find a tree surrounded by butterflies. Disturb them and follow them northeast to a tree. The artifact Galadriel's Lock will be next to the tree.
Bonus Map: Moria
Kill 2,000 enemies with one character to unlock the bonus map, Moria.
Bonus Map: Helm's Deep
Finish the game once with any character to unlock the bonus map, Helm's Deep.
Bonus Map: Weathertop
After finding all eight artifacts, the bonus map, Weathertop will be unlocked.
With Frodo on the level, Slopes of Mount Doom, Go northeast up several stairs and kill the standard bearer at the top. Open the chest. walk back to the begining and go east until you come to Gollum. Open the chest to find the artifact, Deagol's Skull.
Amon Sul Tip
On the bonus map Weathertop, when the wraiths are following you, lead them through the fire in the middle of the level. Walk close to it and turn so that they go through it, then make a big arc and do it again. This is a way to kill them without having to risk them hitting you.
To unlock Smegol on the bonous maps you have to complete the game with Frodo. Smegol is rubbish, he can't equip anything! Its hard to grow levels because the orcs can easily kill Smegol also his attacks do like 1 damage.
You can get all the artifacts in multiplayer except The Witch Crown.