noun
one's own character or vehicle (in a game); player-controlled unit
Used in video games to refer to the character, vehicle, or unit the player is controlling, as opposed to allies or enemies.
自機が敵の弾に当たるとミスになる。
If your ship gets hit by an enemy bullet, you lose a life.
このゲームでは自機のカスタマイズが重要だ。
In this game, customizing your own character is important.
noun
one's own aircraft; the aircraft one is piloting
Used in aviation contexts to refer to the aircraft one is flying, often in contrast to other aircraft. Less common than the gaming sense.
パイロットは常に自機の状態を把握しなければならない。
A pilot must always be aware of the condition of their own aircraft.