This guide was made by Buster WolfBuster Wolf.

Dynasty Warriors 3 is one of few warriors titles to have cheat codes, all of these codes must be entered at the main menu and if successful you will hear a crowd cheering (it you wait awhile after entering).

All Shu Officers: L1, Square, Triangle, R2, L1, L2 , L2, R1, Square, L1.
All Wei Officers: L2, L1, Square, Triangle, L1, L2, R1, R2, L1, L2.
All Wu Officers: Triangle, Triangle, L1, Square, R1, R2, L1, L2, L2, L2.
All Playable Officers: R2, R2, R2, L1, Triangle, L2, L2, L2, R1, Square.
All Stages: R1, R2, L2, L1, Square, L1, L2, R2, R1, Triangle. This also unlocks the side forces as well, but will not unlock the 3 Musou mode specific stages The Mountain Bandit Campaign, Raid on the Rogue Fortress & Pirate Attack on the High Seas.
All BGMs: L1, L1, R1, R1, L2, L2, R2, R2, Square, Triangle.
All Movies: Triangle, L1, Triangle, R1, Triangle, Square, L2, Square, R2, Square.
Opening Edit: R1, Square, R1, Triangle, R1, L1, Square, L1, Triangle, L1.