Dynasty Warriors 4 Cheats

A way I found it easy to level up weapons is to go to one of the levels where you defeat officers and you get 614 points in free mode. And make sure that you have eight strong bodyguards with you because you may need them. After a short period of time, your weapon should be maxed out.

This trick will take quite a long time, but is worth it. Before facing Lu Bu, charge up your Musou. Then, charge towards him (from behind, if possible). Use your Musou on him. After he is on the ground, use this chance to run away. Charge up your Musou again and return to attack him. Your Musou could be more powerful when your life bar is red. This will set Lu Bu on fire.
Take Lu Bu's Red Hare and run back and forth. Run him over and attack with Triangle to get weapon experience or just a normal Square attack. When he is almost dead, you can get off the horse and use Musou, or keep riding horse and lunge at him.
Use the following trick to defeat Lu Bu in a duel. When in Hu Lao Gate, Yuan Shao will say "Protect the ram while it heads for Hu Lao Gate". After the ram destroys Hu Lao's Gate, Yuan Shao will say "All forces march. Take Dong Zhuo's head." After that, Lu Bu will appear. A few seconds, later Lu Bu will say "You dare face the mighty Lu Bu" . Duel him. Use the following items as Zhao Yun on the easy difficulty settin to defeat him. Note: Also use Zhao Yun's Max combo, which is Square(2), Triangle(3). If done correctly, he should fly in the air, allowing you to land another combo. The items are: Tiger Amulet: 15, Tortoise Armulet: 19, Peacock Urn: 15, Dragon Armulet: 15, Wind Scroll: none. Make sure your character has almost maximum stats.
Use the following trick to defeat Lu Bu in a duel. This can be somewhat difficult to actually do, but if it works you can defeat Lu Bu in a duel easily. First, get your character's weapon to at least level 4. Going to all three of the Yellow Turban levels twice (and defeating most, if not all Generals and sub-Generals) should take care of this. Attack Lu Bu with the third charge (Square(2), Triangle) and keep pressing Triangle. You will notice that since the character has the second form of the weapon, they do more hits than before. When Lu Bu becomes dizzy from the last hit, get behind him and do a very strong combo (varies for each character). Keep doing this until he is defeated. Note: Some characters tend to push Lu Bu to the side, thus missing the blow that actually makes him dizzy (for example, Liu Bei, Sun Quan, Guan Yu, etc.). However, this does not make it impossible for them to pull this off.
To defeat Lu Bu in under ten minutes, when the battle of Hu Lao Gate starts, quickly get your gate open by defeating the General that blocks it (Li Ru, Dong Min, etc.). The battering ram should now appear. Kill the General that blocks the Shu army. After killing him, the Shu army should protect the ram. Do not kill the Guard Captains. You will need their health power-ups when fighting Lu Bu. When the gate breaks, quickly hit Lu Bu off his horse. He should now be in rage and pursue you. Do not accept his duels. When fighting Lu Bu non-duel style, just block (L1) all of his attacks. If the light shines, jump and press Triangle for a jump charge. He should now be flying in mid-air. Quickly slash twice before he guards and counter. After jump charging, guard again. It is best for Lu Bu to let him decrease your health to red so you can Musou rather than slashing. Make sure health is nearby. When his life gets low, his Musou attack will shatter your defenses if not blocked correctly. Make sure you are in a stance in front of him. If he Musous, execute your Musou as well if you want to do damage. A stalemate will start; press Square rapidly.
First, get your character to level 8 or lower. Then, get your weapon to level 5 or higher. Finally, level up your bodyguards until you get 8. At the beginning of the battle of Hu Lao Gate, defeat at least four officers. When the ram appears, do not kill the guard captains. Wait until the ram breaks the gate and Lu Bu appears. Knock him off the Red Hare and do not challenge him to a duel. Get him to chase you, and run into only one other General. Get that General to attack him. Keep your distance and try to use your Charge Bow to knock him out (hold R1, then press Triangle). When he is knocked out, go up to him and perform a combo. If your life is red, keep your distance and let the General and your bodyguards attack him. When you get your Musou, use it on Lu Bu. Keep doing this until he dies. You can kill a Guard Captain to heal.

A way I found it easy to level up weapons is to go to one of the levels where you defeat officers and you get 614 points in free mode. And make sure that you have eight strong bodyguards with you because you may need them. After a short period of time, your weapon should be maxed out.

To get Lubu Max Life/ Atack/ Musou Play Lubu with his Level 10 Sky Skorchor in Free Mode Kill over 100k.o.

When dealing with magical obstacles; i.e.: boulders, floods, wind
storms kill the magician that made it to deactivate the obstacle.
When it's military; i.e.: catapults, fire juggernauts, free-standing
forts. Destroy it with you're character attack.

These should be done on the Hard difficulty setting and characters should already have their level 9 weapons:

Da Qiao
Play the Battle Of Xu Chang level on the Wu side. Defeat Deng Ai, Hu Zhi, and Dian Wei.
Dian Wei
Play the Battle Of Wan Castle level. Defeat Hu Che Er, then join with Cao Cao. After the Cao Cao conversation with Dian Wei event, deplete about half of Zhang Xiu's HP and he will retreat. After the castle gate closes, clear the map of enemies for Cao Cao to advance. After Cao Cao reaches the dead end, two fire blocking exit messages will appear. After the Xu Chu breaks through wall event, Dian Wei earns his Level 10 Weapon.
Dong Zhou
Play the Lu Bu's Revolt level. Kill everybody on the screen where Lu Bu is the only one alive. If done correctly, Dong Zhou will make a comment.
Guan Yu
Kill all the Wu generals at the Fan Castle level. Make sure that all your soldiers switch sides before you kill the Wu generals.
Huang Gai
On the Battle Of Chi Bi level, eliminate all enemy entry points before the fire attack, then defeat Cao Ren, Cao Hong and Cao Pi.
Lu Bu
Play the Lu Bu Rebellion level. Clear the entire stage of every enemy so that only Dong Zhuo remains alive. Be sure to kill every general and sub-general yourself. Lu Bu will earn his Level 10 weapon. Note: If the weapon does not appear after only Dong Zhuo is alive, move around the map awhile. There may still be ambush troops you did not encounter.
Lu Xun
On the Battle of Yi Ling level, protect and keep Zhu Ran alive until he successfully triggers the fire attack. Enter stone maze, and pass through it.
Ma Chao
In the Chen Du Suppression level go to the left side of the map to trigger the appearance of enemy back-up troops. Kill the enemy back-up troop generals Pang De and Ma Dai. Note: This can only be done in Musou mode, because the generals will be Ma Chao and Ma Dai in free mode.
Meng Huo
Play the Battle Of Cheng Du level as Meng Huo on the Nanman Forces. Kill every character that is playable. Note: Make sure you personally kill the character and have his level weapon. You will get his level 10 weapon, King Of Beast.
Pang Tong
Play the Battle Of Luo Castle on the Shu side. When Zhang Ren appears, decline his duel challenge. Destroy the bridge and kill Zhang Ren.
Sima Yi
Ho to Battle Of Wu Zhang Plains level and defeat Wei Yan, Jaing Wei, and Ma Chao. A message will appear, stating that Dark Feather has been unlocked.
Sun Jian
Play the Search For The Imperial Seal level with Sun Jian. You must defeat Li Jue, Zhang Liao, Diao Chan, and Lu Bu. Finish the level with Sun Jian's level 9 weapon to get his level 10 weapon.
Xiahou Dun
On the Battle of Xia Pi level, after the Xiahou Dun shot by an arrow event, defeat Diao Chan.
Xiahou Yuan
On the Battle of Mount Ding Jun level, immediately kill the exchanging hostage Chen Shi. Then move directly to Huang Zhong. Defeat Huang Zhong.
Yuan Shao
Play the Battle Of Guan Du level as Yuan Shao. Protect the ramming vehicle until the castle wall falls. You will then get the Sword Of Kings.
Zhang He
On the Battle Of Jie Ting level, surround Ma Su and defeat him. Then, defeat all enemy generals and sub-generals.

Have a level nine weapon and want level ten here is how to get some.
To get these weapons
•Play on hard difficulty.
•Character must already have Level 9 weapon.
•Must play on characters kingdom.
•Works on free mode or muso mode (unless I say below it)
Shu:
Guan Yu
Level = Battle of Fan Castle
How to get = After all ally generals defect (except for Guan Ping and Zhou Cang), defeat all three Wu back-up troop generals in any order.
Ma Chao
Level = Campaign for Cheng Du
How to get = Reach the left side of the map to trigger the enemy back-up troops appearance, defeat enemy back-up troop generals Pang De and Ma Dai.
Note = This weapon can only be earned in Musou Mode. If you play Free Mode, the back-up troop generals will be Ma Chao and Ma Dai.
Pang Tong
Level = Battle of Luo Castle
How to get = First run up to one of the gates of the top left castle, castle gates not opening message, defeat Liu Kuei or Zhang Yi, Pang Tong enrages Zhang Ren messages, Zhang Ren attack message, lead Zhang Ren across the Northern verticle bridge (Jing Yen Bridge), bomb preparation complete message, stand near the bridge, bridge destruction event, Zhang Ren starts to retreat message, defeat Zhang Ren.
Wei Yan
Level = Campaign for Jing
How to get = Defeat enemy ambush troop general Xing Dao Rong, defeat Liu Du and Liu Xian, do not defeat Jin Xuan (decline duel), defeat Han Xuan's sub-general Yang Ling, Huang Zhong exit castle and attack message, defeat Huang Zhong, Wei Yan and Huang Zhong defect event.
Note = This weapon can only be gotten on free mode.
P.S. More to come