Prince of Persia: The Two Thrones is a 2005 action-adventure game developed by Ubisoft Montreal and Ubisoft Casablanca, and published by Ubisoft for the PlayStation 2, GameCube, Microsoft Windows, Xbox and Java (mobile phones only). It was later ported to the PlayStation Portable and Wii in 2007 under the title Prince of Persia: Rival Swords. The Wii version utilizes the motion-sensing functionality of its controller, while the PSP version added exclusive content and local multiplayer.

The Two Thrones is the sixth main installment of the Prince of Persia series, and the final chapter of the Sands of Time trilogy, but is not the last game to be set in its continuity. The story follows the Prince as he returns to his home in Babylon, only to find that his actions in Warrior Within have undone the events of The Sands of Time. The villainous Vizier is back from the dead and kills the Prince's companion Kaileena, absorbing the Sands of Time from her, which transform him into an immortal monster. Now, the Prince must work together with his past love Farah (whom he meets for the first time in this new timeline) to defeat the Vizier once and for all, while also struggling against his own Dark Prince persona, which is slowly corrupting him.

Upon release, the game received generally positive reviews, with praise for its story, characters, level design, graphics, combat and new speed kill mechanic, but the PSP and Wii versions reviewed significantly worse than the others. This installment of the game was also a commercial success, selling over 1.5 million copies within one month of release. Following The Two Thrones, the series was rebooted a second time with 2008's Prince of Persia. The series returned to the Sands of Time continuity with 2010's Prince of Persia: The Forgotten Sands, which is set between the events of The Sands of Time and Warrior Within.

The game combines exploration and combat. Both elements make use of the Prince's acrobatic capability and agility. For much of the game, the player must attempt to traverse the palace by running across walls, ascending or descending chasms by jumping back and forth between walls, avoiding traps, climbing structures and jumping from platform to platform, making other types of well-timed leaps, solving puzzles and using discovered objects to progress. There are also a few on-rails sequences where the Prince must ride a chariot along a long stretch of road at dangerously fast speed, requiring the player to avoid obstacles and fend off enemies along the way.

During combat, many of the same moves vital to the player in other situations can be put to use to overpower enemies. An example is the ability of the Prince to jump off walls in order to strike enemies decisively. The player generally attacks enemies and blocks using a dagger, although other objects or factors, such as the Dagger of Time and its time-control abilities eventually prove to be critical to victory. The Dagger of Time can also be upgraded by disabling "sand gates" that enemies may use to summon reinforcements, which will increase the number of sand charges it can hold for its powers and eventually unlock two new abilities that consume multiple sand charges to damage or destroy multiple enemies at once. Continuing the freeform fighting style employed in Warrior Within, the Prince can also obtain secondary weapons from defeated enemies or weapon racks and use them in dual wield combat, with most weapons having limited durability and becoming unusable after a certain amount of hits, or after they are thrown as projectiles or dropped when the Prince turns into the Dark Prince. The Wii version of the 2007 port, Rival Swords, implements attacks with generic shakes of the Wii Remote and Nunchuk, with the former swinging the Dagger and the latter swinging the equipped secondary weapon.

In The Two Thrones, the Prince's acrobatic skills have improved and he is now able to launch himself off walls at 45 degree angles at strategically placed vertical shutters, slide down chutes and balance on swinging poles, among other things. The designers have also improved the stealth system. Instead of merely being able to do more damage when striking without being seen, the game uses a Speed Kill system to provide a single opportunity to instantly defeat an enemy or two. To succeed in doing so, the player must press the attack button at certain times (with the number of required hits and the intervals between each attack cue depending on the target); failure to do so results in the target throwing off the Prince. The same system is also integral to dealing damage in some of the boss battles. Attacks against enemies feature graphic violence effects that can be toggled in the in-game options menu, but are removed in Rival Swords.

The Prince also develops a split personality, known as the Dark Prince, and this alter ego constantly bickers with him in his mind about right and wrong as just an inner voice for most of the time. At certain times, the Prince will automatically and physically transform into the Dark Prince, which the player cannot do at will. During these times, however, the Prince retains control of his body, and the player still has control over the character. When controlling the Dark Prince, the player loses the ability to wield a secondary weapon, instead using the "Daggertail", a bladed whip fused to his arm. This special weapon can slash enemies at mid-range and is critical to pulling blocks out of walls and grappling along torches or high bars to cross long gaps. The Dark Prince also constantly loses health as a result of the semi-transformation, with eventual death from the loss. He goes back to full health whenever he collects Sand, from either a monster or object. Also, his Daggertail has a different control scheme for speed kills, in which the player repeatedly presses the attack button to make him saw off the heads of his victims (or strangle them if blood effects are disabled) with this weapon. The Prince will turn back to normal upon stepping into water, which cannot be avoided.

Throughout the game, the Prince can find up to six branching side routes to earn health upgrades, as well as earn sand credits to unlock concept art by collecting sand charges, destroying sand chests and disabling sand gates throughout the city. The Prince can only recover health by drinking water from certain areas or at save fountains, but can also fully recover health when changing to and from the Dark Prince. If the Prince or Dark Prince dies from losing all health, a chariot accident or a fatal fall and the player is unable or unwilling to use the Dagger's recall power to reverse his demise, play continues from either the last save fountain he used or checkpoint he passed, with a few of the latter present between most save fountains.