任天堂紅白機(FC)遊戲《忍者龍劍傳》(忍者龍剣伝/ニンジャガイデン/Ninja Gaiden)的主要密技：

1.在遊戲中使用旋風斬道具時，當與頭目對戰時，只需跳起來按下攻擊鍵，就能對頭目造成大量傷害。這個技巧的殺傷力過強，在續作中直接被移除。

2.在第5-3關的第三層塔樓，有一個增加一生命數的UP道具。拿到後沿著梯子回到二樓，然後再返回三樓時，仍然會看到UP道具。持續操作就能獲得無限生命數。

3.當首頁畫面出現時，同時按住左鍵、下鍵、A、B和Select。按下開始鍵時，就能進入音樂測試畫面，聆聽遊戲中的各種音樂。

Main cheat codes for the Nintendo Entertainment System (NES) game "Ninja Gaiden" (忍者龍剣伝/ニンジャガイデン):

1.When using the whirlwind slash item in the game, during boss battles, simply jump and press the attack button to inflict a large amount of damage on the boss. This technique's killing power is too strong and was directly removed in subsequent versions.

2.In the third tower of level 5-3, there is an UP item that adds one life. After obtaining it, climb back down to the second floor using the ladder, and then return to the third floor. The UP item will still be visible. Repeating this process will grant you unlimited lives.

3.When the title screen appears, simultaneously press the left key, down key, A, B, and Select. Press the start button, and you will enter the music test screen, where you can listen to various tracks from the game.