Ninja Gaiden II: The Dark Sword of Chaos, known in Europe as Shadow Warriors II: The Dark Sword of Chaos, is a 1990 platform game developed and published by Tecmo for the Nintendo Entertainment System. It is the second instalment in the Ninja Gaiden trilogy for the NES and was released in North America and Japan in 1990, and in Europe in 1994. An arcade version was released by Nintendo for their PlayChoice-10 system in 1990.
The events in Ninja Gaiden II take place one year after the events in the first Ninja Gaiden game. The story involves an evil emperor named Ashtar who, after hearing of Jaquio's defeat, devises a plan to take over the world and engulf it in darkness through an evil sword called the Dark Sword of Chaos. A U.S. Army agent named Robert T. Sturgeon recruits the game's protagonist Ryu Hayabusa and tells him that he is the only person who can stop Ashtar.
Ninja Gaiden II received praise in previews from Electronic Gaming Monthly and Nintendo Power and continued to receive high ratings and coverage, being nominated for several awards from Nintendo Power in 1991. Reviewers said that the game's visuals and controls were improved over its predecessor while maintaining a high level of difficulty for players, but the plot was criticized for being more generic and predictable. The game maintains lasting appeal among players, with one reviewer saying that Ninja Gaiden II is "a challenging experience the likes of which gamers in the 8-bit era lived and died for". It has been rereleased via the Virtual Console, Nintendo Classics and Console Archives services. A sequel, Ninja Gaiden III: The Ancient Ship of Doom, was released in 1991.
Plot In the Realm of Darkness, Ashtar, the evil lord who controlled Jaquio, is informed of Jaquio's defeat; he devises a plan to rule over Earth by opening the Gate of Darkness.Strategy Guide, pp. 5–7. "Ashtar: The time shall come ... when the Gate of Darkness is cast open ... all men shall kneel before me ... and shall hail me, Ashtar, as their new master!" A U.S. Army Special Intelligence unit member named Robert T. Sturgeon is sent to find Ryu to take out Ashtar.Strategy Guide, p. 9. Robert informs Ryu that Irene Lew has been captured and that he must go to the Tower of Lahja to save her.Strategy Guide, p. 19. After hopping on a freight train and then battling up the mountain in which the tower lies, he is ambushed by a figure who describes himself as a tribesman of the World of Chaos, led by the Emperor of Darkness Ashtar.Strategy Guide, pp. 22, 24, 28. "Baron Spider: We are tribesmen from the World of Chaos, led by the Emperor of Darkness Ashtar ..." After making it to the top of the tower, Ryu finds Irene, who has been captured by Ashtar. Ashtar then blasts Ryu with energy from his own sword; before Ashtar can finish off Ryu, Robert appears and shoots Ashtar in the back, stopping him. Robert orders Ashtar to hand over his sword and give up, but Ashtar escapes with Irene, telling Ryu to follow him into the Maze of Darkness.Strategy Guide, pp. 37–38. "Ashtar: Ha, ha, ha! If you want the sword, you'll have to follow me ... into the Maze of Darkness!"
After Ashtar escapes into the Maze of Darkness, Robert tells Ryu about Ashtar's plot to take over the world by using the full power of his sword, the Dark Sword of Chaos.Strategy Guide, p. 41. After battling through the Maze of Darkness and into the World of Chaos, Ryu hears echoes of Ashtar's plan in the distance.Strategy Guide, p. 55. Ryu then catches up with Ashtar. He releases Irene, but immediately after releasing her he stabs her with the Dark Sword. Robert then shows up, only to find out that Irene has been mortally wounded; Ashtar then blasts Robert with energy from his Dark Sword and then challenges Ryu to battle.Strategy Guide, pp. 58–61. Ryu defeats Ashtar, and before he dies, he says that the forces of Darkness will soon awaken and implores the forces of Chaos to engulf the world into darkness.Ninja Gaiden II: The Dark Sword of Chaos. "Ashtar: The Force of Darkness shall soon awaken. No one will be able to stop it. Join forces, Shadows of Chaos. Swallow this world into Eternal Darkness..." While he is saying this, the Dark Sword of Chaos vanishes into thin air. After Ashtar's death, Irene tells Ryu that an evil altar that Ashtar prepared to open the Gate of Darkness must be destroyed.Strategy Guide, p. 64. Ryu then leaves Irene behind and tells Robert to take her and leave the World of Chaos.Ninja Gaiden II: The Dark Sword of Chaos. "Ryu: Alright ... I'll go, Irene. But I'll come back for you as soon as I can. Robert, take Irene and get out of here now".
As Ryu enters the World of Darkness, Irene and Robert, while traveling back, are stopped by a shadowy figure that Irene has seen before. Meanwhile, after defeating Kelbeross whom he noted he fought in his showdown with Jaquio, Ryu finds Robert on the ground and mortally wounded. He tells Ryu that Irene has been captured again and that Ryu must prevent the Gate of Darkness from opening. Robert then tells Ryu to leave him behind while he fends off the demons.Ninja Gaiden II: The Dark Sword of Chaos. "Robert: Ryu. If the Gate of Darkness is opened, the Tribe from the dark world will cause chaos. That'll be the end of all mankind. Hm ... listen! They're coming again. And there are quite a few of them. I'll stay here and hold them off. Ryu, you get going". Ryu eventually makes it to the evil altar where he finds Irene and the shadowy figure who captured her; the figure reveals himself as Jaquio, who was possessed by the demon after his first battle with Ryu.Ninja Gaiden II: The Dark Sword of Chaos. "Jaquio: The spirit released after our battle flowed into my body. I am reborn. And I've got the dark Power of Evil".
Jaquio tells Ryu that he plans to use the Dark Sword of Chaos to exploit Irene's life force as a means to open the Gate of Darkness and summon all the demons, while Ryu awakens them from their sleep.Ninja Gaiden II: The Dark Sword of Chaos. "Jaquio: The spirit you defeated before was nothing more than a pawn. Your battle served only to awaken the ancient, true Spirits of Evil. The Sword of Chaos simply sucks up your life force. And when the Sword awakens, the Gate of Darkness shall be thrown open ... And the demons shall come back to life.... Her life force shall be used to call up the demons. You shall awaken them, she shall call them back to earth". Jaquio then challenges Ryu to a showdown in which Ryu defeats him. Before Ryu and Irene can destroy the evil altar though, Jaquio's blood awakens the Dark Sword, which opens up the Gate of Darkness, shocks Irene and Ryu with its energy. The Demon Jashin reanimates the corpse of Jaquio, turning him into a demonic wall, which Ryu, after borrowing strength from his Dragon Sword, defeats. Jashin is once again sealed away, the Dark Sword then breaks apart, the Gate of Darkness closes and disappears, and Ryu flees with Irene out of the temple just as it collapses. He then begins to mourn for Irene, who is presumed to be dead, when the power of the Dragon Sword revives her.Ninja Gaiden II: The Dark Sword of Chaos. "Irene: Ryu. What ... what happend [sic] to me? I feel like I've been dreaming ... for a long time". Ryu tells her that the incident is over as the two watch the sun set.
Gameplay
As with the previous Ninja Gaiden game, the player controls Ryu Hayabusa through a series of platforming levels called "Acts". Players have the ability to jump and latch on and off walls and ladders.Instruction Manual, p. 11. Two new abilities that Ryu can do in Ninja Gaiden II are climbing up and down walls and attacking with "Power Boosting Items" while on walls and ladders. Ryu has a strength meter on top of the screen that decreases whenever he takes damage from enemies. The player loses a life if Ryu's strength meter runs out, Ryu falls off the screen or if the timer runs out; the game ends if players lose all their lives.Instruction Manual, p. 8. The player can continue and restart the game from the beginning of the level in which they lost all their lives.Instruction Manual, p. 21.
Players dispatch enemies by either thrusting at them with Ryu's Dragon Sword or by defeating them using Power Boosting Items. These special items consume Ryu's "ninja power", also located on the top of the screen. Power Boosting Items include the following: shurikens; "Windmill Throwing Stars" that move back and forth like a boomerang; "The Art of the Fire Wheel" which hurls fireballs diagonally upwards; "Fire Dragon Balls" which hurls fireballs diagonally downwards; and the "Invincible Fire Wheel" that creates a barrier of three fireballs around Ryu, destroying any enemy that touches them.Instruction Manual, p. 16. These items can be found in various crystal balls scattered throughout the levels, and they can be switched out by collecting another Power Boosting Item. The amount of ninja power used depends on the type of Power Boosting Item used.Strategy Guide, p. 13. At the end of each Act Ryu fights a boss which has its own strength meter, located on the top of the screen. The boss's strength meter decreases every time the player damages it, and the boss is destroyed when the player completely depletes its strength meter.
Along the way, the player can collect items that are found in crystal balls scattered throughout the levels. These items include the following: items that increase Ryu's ninja power; bottles that increase the player's score; "Scrolls of the Spirit of the Dragon" that increase Ryu's maximum ninja power; medicine that partially refills Ryu's strength meter; Power Boosting Items; and 1-ups.Instruction Manual, pp. 13–15.Strategy Guide, p. 12. Another new feature in Ninja Gaiden II is the ability for Ryu to "split his body" and clone himself when the player collects an orange ninja symbol. Collecting this symbol creates for Ryu an orange shadow of him that follows behind and copies every move Ryu makes, including climbing walls and ladders and attacking enemies. Using this technique, the player can strategically position Ryu and his clones to more easily defeat enemies and bosses.
Release Electronic Gaming Monthly previewed Ninja Gaiden II in late 1989 and early 1990. The game first appeared in its September–October 1989 issue and again in its November issue; they noted the new levels, power-ups, and an "explosive story that's loaded with twists and turns". In the magazine's January issue, Steve Harris praised the game for its new power-ups, scrolling backgrounds, and more detailed cinematic cutscenes. He said that the game was going to take the series "one step further than before". The game was shown to the public for the time at the Winter 1990 Consumer Electronics Show in Las Vegas, in which Nintendo Power gave "four star ratings for its great cinema scenes and challenge". The same magazine previewed the game in its "Pak Watch" section in their March–April 1990 issue. They said that at first look the game had better cutscenes than the first Ninja Gaiden game, and they noted the great and diverse gameplay and high level of challenge.
Nintendo initially introduced Ninja Gaiden II as an arcade video game for their PlayChoice-10 system at Chicago's American Coin Machine Exposition (ACME) in March 1990, marketed as a sequel to Tecmo's hit Ninja Gaiden arcade game (1988). The NES version was then released in Japan on , in North America in May 1990, and in Europe on . Ports were published for the Amiga and MS-DOS by GameTek in 1991. It has been digitally re-released multiple times via the Virtual Console storefront, including in 2007 for the Wii, in 2013 for the Nintendo 3DS, and in 2016 for the Wii U. It was added to the Nintendo Classics service on November 26, 2025. Hamster Corporation re-released the game for the Nintendo Switch 2 as part of their Console Archives series in February 5, 2026; followed by a re-release of the game on PlayStation 5 in February 14 of the same year.