Gameplay
Gameplay for Guitar Hero III: Legends of Rock is similar to previous titles in the series. The player hits notes as they scroll towards the bottom of the screen in time with music to maintain their performance and earn points. To hit notes using the guitar controller, the player hits the strum bar while holding down the corresponding colored fret buttons. If the player uses the standard controller instead of the guitar controller, the correct buttons need to be pressed, but the player is not required to strum. Notes can be sustained, during which the fret button is held until the note is complete, and they can also form two- to four-note chords. The game simulates hammer-ons and pull-offs for sections with a rapid series of notes, allowing the player to forgo strumming on specifically marked notes. Missing a note causes the performance meter to drop. When the meter drops too low, the player fails the song, represented in-game by the band being booed off the stage. A string of 10 consecutive correct notes earns a multiplier to increase the player's score, which can occur up to four times. Special sections, marked by starred notes, can be used to build Star Power. When the player has enough Star Power, they can activate it and further double the scoring multiplier either by tilting the guitar controller vertically or by pressing a specific button on the controller. While Star Power enabled, the performance meter increases more quickly when a correct note is hit, and missing notes have a decreased penalty. Guitar Hero III: Legends of Rock contains four difficulty levels: Easy, which uses three of the fret buttons; Medium, which makes use of four of the fret buttons; Hard, which uses all five fret buttons; and Expert, which adds no new fret buttons, but increases the number of notes and the general difficulty.
During a song, avatars of the virtual band, including one character selected by the player, will perform in time to the music, responding appropriately to the unleashing of Star Power or the failing of a song. Guitar Hero III: Legends of Rock has a cast of thirteen characters, which the player can further customize with alternate guitar skins and stage outfits using in-game money earned from successful performances. The player can access the game's three boss characters—Tom Morello, Slash, and Lou the Devil—as playable characters once they have completed their respective Boss Battles in Career mode. Although Bret Michaels appears in the game and sings specific songs, he is not a playable character in the game.
Career Mode
The single-player Career mode in Guitar Hero III: Legends of Rock features 8 tiers with 42 songs total. Within each tier, the player completes a number of songs, the number depending on the selected difficulty level, before they are offered an encore performance of one additional song and complete the tier. After a tier is complete, a new tier is introduced. Guitar Hero III: Legends of Rock includes Career mode boss battles based on the game's multiplayer Battle mode; at three points during the Career mode, the player must compete against a boss character to progress. Each successfully completed song earns in-game money that the player uses at the game's store to unlock new characters, outfits, guitars and finishes, bonus songs, and videos. Additionally, completing a song in Career mode unlocks it for play in all other game modes.
Guitar Hero III: Legends of Rock is the first game in the series to feature a storyline for the Career mode, portrayed through animated cartoon scenes between venues produced by Titmouse, Inc. Studios. The band starts as a neighborhood sensation, and after signing a recording contract with a shady music producer named Lou, gains worldwide fame, performing at venues around the world. However, when the band attempts to break the contract, Lou reveals himself to be the Devil, and their recording contract is actually a contract for their souls. Lou forces the band to play against him in the netherworld at "Lou's Inferno", but the band is able to succeed, forcing Lou to break the contract. The band returns to the mortal world as "Rock Legends".
Two players using the same console can participate in Co-Op Career mode, with one player on lead guitar and the other on bass or rhythm guitar depending on the song. There are six tiers of songs which the players complete in the same manner as the single player Career mode. The encore song for each tier is unique to Co-Op Career mode. There are no boss battles in this mode. The animated Co-Op storyline portrays the vocalist and drummer, who are looking for a guitarist and bassist. After their first performance, the drummer decides to make a video of the band. The video helps boost the band's popularity, and they soon earn a gig in Japan. The band is forced to take a three-month hiatus to reconcile their differences of opinion on the band's future. Their comeback performance starts a neighborhood fire and places the band in jail. Lou arrives, offering the band to be freed from jail if they perform for the inmates. However, after their performance, the band finds themselves in Lou's Inferno, and is forced to play a live show for the netherworld in order to return to the mortal world.
Multiplayer
The Xbox 360, PlayStation 3, and Wii versions of Guitar Hero III: Legends of Rock feature online competitive play, in which the player can compete against another user through the console's network service. There are three modes of online play, Face Off, Pro Face Off, and Battle mode. Face Off challenges are score attack modes introduced in Guitar Hero II where two players attempt to gain the best score on a given song; in the standard Face Off challenge, the players may select different difficulty levels, while Pro Face Off requires the players to play at the same difficulty.
The Battle mode in Guitar Hero III: Legends of Rock is a competitive mode between two players either locally or over network play. Two players compete against each other and attempt to make their opponent fail or lose by successfully playing Battle Power sequences, which replaces Star Power sections, to earn attacks that can be used against the opponent. Players can store up to three attacks at a time, and release them by using the same methods used to trigger Star Power in normal gameplay. The resulting effect may either make the song more difficult for the other player by adding additional notes or partially displaying the gem tracks, or may force the opponent to perform special actions to clear the effect, such as by pressing a fret button down repeatedly in response to a broken guitar string effect. Should a player fail the song, the other player wins. If neither player fails the song, they compete in a Sudden Death segment, in which the only attainable Battle Powers are Death Drain attacks, which inevitably makes the opponent fail by draining his or her Rock Meter.
