Animated Flying Sword

An animated flying sword on the party's side usually means a wizard PC built one, an artificer commissioned a guardian, or an old NPC mentor lent them their workshop's house defender for a night. It does exactly one thing: float at the assigned target and Slash. Treat it as a semi-autonomous magic item, not a sidekick.

Give it a single standing order each combat. "Guard the unconscious cleric." "Attack any creature that crosses this rope." "Stay within 10 feet of the rogue." Anything more nuanced exceeds Int 1, and players who try to micromanage it should get blank obedience to the literal words. The sword has Blindsight 60 ft., so it makes a strong sentry in dark crypts and underwater corridors where the party's torchbearer is exposed. Out of combat it cannot scout, talk, or open doors.

In a fight, position it to flank with a melee PC for advantage on Slash and to screen casters at the back rank. AC 17 means low-CR enemies bounce off, but 14 HP evaporates against anything with a real damage roll, so don't let it tank. The construct immunities make it the safest minion to send into a poison cloud, a ghoul's paralysis aura, or a mind flayer's psychic blast. When it drops, it drops without ceremony, and the party loses a tool rather than a friend.

If the players grow attached, let the sword survive a session or two and then have it shatter on a high-stakes save the party needed to make. The clean death is better than slow obsolescence.

An animated flying sword is a trap with a stat block. It exists to make a corridor or treasure room feel haunted before the party even sees a real enemy, and it works best when the players don't know how many of them are about to peel off the rack.

The sword has Int 1 and no language, so it follows whatever standing order its creator left: guard the door, attack anyone holding the wrong amulet, kill until destroyed. It hovers at 50 ft. of fly speed, ignores difficult terrain, and Blindsight 60 ft. means darkness, invisibility, and obscurement do nothing. Open by floating through a wall sconce or off a weapon rack on initiative count, full move into reach, then Slash at +4 for 1d8+2. AC 17 is high for CR 1/4, so the first miss against it tells the players this isn't a normal mook. HP 14 is low; a single greatsword crit can drop one. Run them in pairs or trios so the party still feels the threat on round two.

Immunity to Charmed, Frightened, Paralyzed, Petrified, Poisoned, and Psychic shuts down most caster control. The sword does not flee, parley, or surrender. If the bearer of its activation token leaves the room, it stops mid-air at the last position and waits, which is creepier than chasing. Use that pause. A sword that hovers motionless three feet off the floor while the party debates is more memorable than one that obediently dies.

Telegraph the activation. Have a faint hum start two rounds before initiative, or a chalk circle on the floor flare red the moment a PC steps inside. The reveal is more interesting than the fight.