Sekigahara

The Battle of Sekigahara (関ケ原の戦い, Sekigahara no Tatakai) is largely considered to be one of the most decisive battles in the late Sengoku period. Essentially, it is a power struggle for the right to rule the land after Hideyoshi's death.

Samurai Warriors
There are many possible outcomes to this battle in Samurai Warriors 2, but there are also certain events that remain consistent in most scenarios. Near the start of the battle, each army desires to protect their cannons while claiming the opposing army's artillery for their own. Ieyasu will order Magobei Fuse to fire at Mount Matsuo, in which Kobayakawa remains indecisive in a garrison. If the ploy fails, he will send Hanzō to threaten the man. If the Eastern Army succeeds in any of these schemes, Kobayakawa will defect and the morale for the Western side will decrease dramatically. Players are additionally given the option to allow or prevent Mori and Kikkawa switching allegiances by dealing with Ekei. Ginchiyo will also choose to charge the Eastern camp from the north, which may hamper the Eastern army's progress.

Officers for the East may also choose to protect Naomasa Ii and Masanori Fukushima as they perform an overzealous charge against Mitsunari; losing them will lower ally morale. Yoshihiro will decide to retreat and pave his way through the Eastern Army if the Western Army begins to crumble. He will instantly route any NPC officer that he runs into, warning them on each instance to get out of his way. Defeating him is optional and he will die if the player chooses to do so. The East claims victory on Mitsunari's death and expand the Tokugawa's influence, eventually leading to the Siege of Osaka.

Generally, the Western Army officers will be given the chance to route Ieyasu's forces by countering the Eastern Army's strategies. Ina will await in the upper-left garrison and charge downwards for the Western camp after some time passes. If the Eastern Army fares badly, Tadakatsu will ride to the center of the battlefield to raise the morale of his comrades. During this time, every Eastern officer will be in hyper mode and Mitsunari orders the player to stop Tadakatsu. Following his defeat, they can also pursue him at Edo Castle. There's also the instance where Ieyasu also dies upon his defeat such as in Motochika's story mode.

Musashi begins his story here as a warrior on the fallen Western side and has to fight for his survival.

Major differences can also occur in certain characters' dream stages such as Yukimura, Nene, Masamune and Yoshihiro's.

Warriors Orochi
In Warriors Orochi 2, it will serve as the final stage for the Samurai story mode. Sakon will lead the united Shingen, Kenshin and Nobunaga forces to defeat the resurrected Orochi.

Kessen
In Kessen, this battle will decide who lives or dies for the remainder of the game's campaigns. The concepts of the Western and Eastern army remain after the battle's conclusion. In the Tokugawa camp, the pre-battle cutscene dramatizes the former Toyotomi general's reasons for joining Ieyasu. Moments before the battle commences, Ieyasu sees a vision of Nobunaga bidding him to continue his legacy. Determined to win, Ieyasu draws out his sword and, whilst declaring his desire to rule, cleaves the mist enshrouding the battlefield. Scoring a victory in this battle acts as the first step for Ieyasu's path as shogun.

By contrast, the Western Army scenario touches on some of the generals' conflicting feelings regarding Mitsunari. Undeterred by news of betrayal amongst their ranks, Mitsunari marches into battle. He swears to protect the Toyotomi family and repay his debt to the late Hideyoshi. If Mitsunari wins this battle, he will pursue the fleeing Ieyasu with reinforcements from the Sanada troops. Losing any major battle after this will usually result in Mitsunari, Sakon, or Otani's deaths. Winning every battle for the Toyotomi side will secure their family's reign by Mitsunari's hand.

Depending on the actions of the player, the armies will fight at Sekigahara again as their final battle.

The area serves as a battle ground twice in Kessen III. While escorting his sister to her future husband, Nobunaga has to simultaneously protect her from his rivals. He returns here once more after the incident at Honnoji to "revive" his name to the public eye and surprise the Akechi troops.

Saihai no Yukue
Sekigahara is the main setting for Saihai no Yukue. The player sees the game from Mitsunari's point of view which villainies Ieyasu. The story explores characters and famous events before the main confrontation. Though Mitsunari is routed by Ieyasu, he escapes capture and reappears with three generals. He turns the tide of the battle and ends the conflict by sunset the same day.