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How to Beat Rom, the Vacuous Spider in Bloodborne

How to Beat Rom, the Vacuous Spider in Bloodborne

Don’t be fooled by the boss’s name, Rom the Vacuous Spider isn’t as mindless of an insect as his name and initial interaction suggests. Rom is one of the more surprisingly difficult non-optional boss fights in Bloodborne, catching you off guard with his army of spiders and devastating magic attacks.


Nonetheless, he is a manageable boss if you know what he has under his belt and we are here to spill the beans. Get ready to crush this arachnid with your boot Hunter!

Fighting Rom, the Vacuous Spider

Rom, the Vacuous Spider Bloodborne

When you drop down into Rom’s vast arena, you’ll see him poof in, standing in place with a horde of mini spiders protecting him. Maneuvering through the army of arachnids is the real challenge for this boss initially.

You can ignore them if you want but their sheer number will hinder your direct engagement with the boss. The boss will remain passive during the start of the fight even when you are hitting him.

After you have lowered his health to 66%, he will teleport to another location, and now he gets angry. Not only will he spawn more spiders but starts using magic spells that hurl giant boulders at you.

He only has a few attacks, but each one has the potential to one-shot you, so be careful. You need to be extra vigilant when attacking him this time around.

He will teleport at around 33% health again, spawning a new horde of spiders upon his arrival and adding a new attack to his repertoire. The fight is generally the same from this point.

Here are some tips you can use when facing Rom the Vacuous Spider in Bloodborne:

  • The boss is weak to Bolt damage. Carry and apply Bolt Paper during this fight to exploit this weakness.
  • Arcane-resistant armor sets, like the Tomb Prospectors, will help absorb some of the damage from his magic attacks.
  • You can largely ignore the smaller spiders in the arena and only clear out the ones that can pose a threat to you while you confront the boss.
  • Shaman Bone Blades can be thrown on a mini-spider, turning the enemies’ attention towards the inflicted spider. You can use this time to lay into the boss.
  • His body is weaker than his head so focus your attacks on the body only.
  • He will take his sweet time to teleport. Do not stop attacking him at this point, he will continue to receive damage.
  • Weapons that have the “VS Kin” attribute will deal more damage.
  • The mini spiders can stun-lock you if they simultaneously start performing the headbutt move. It could spell instant death for you.
  • You can summon Mensis Scholar Damien to help you during this fight.

Boss Strategy

Rom, the Vacuous Spider Boss Strategy

The fight will become even more comfortable if you have an upgraded pure Blunt weapon like the Kirkhammer. When he is about to teleport, a well-timed charged R2 attack will thwart his attempt to vanish and you can continue to whale on him.

When he tries to teleport again just keep repeating the charged attack strategy and there will be no later stages of this fight. He will go down without ever attacking once.

For others with different weapons, you must equip Bolt Papers to your quick select slots and apply it constantly. Beastblood Pellets will increase the damage of subsequent attacks too so keep some of them too.

In the the first instance, he will be passive so there is no danger from him only the waves of spiders. Run up to the boss, clear any spiders in your vicinity, and start attacking his body until he fully teleports. You can leave the other spiders that pose no threat.

When he returns, he will start lobbing boulders at you and summon a new wave of spiders. The best way to outmaneuver the projectiles is to run toward the boss in a left slant. The boulders will fly by if you do it correctly.

Again, clear any pesky spiders in the way and start attacking the boss. This time you need to be careful of the boulder rain and the boulders that spawn straight up from the ground around him.

These attacks have very clear telegraphs and indications so react accordingly. Run to the sides for the rain and back off when he is about to burst the ground boulders. Keep attacking in between his attacks and soon he will teleport for the last time.

When he comes back, this time he has a few more AOE attacks that you must be careful of and a new horde of spiders. One of these attacks is an AOE explosion which you need to run away from or else you are done for.

This phase is the same as the second where you have to look out for his magic attacks and keep up the pressure in the windows in between. With enough damage in, Rom will soon evaporate and the world will change with the arrival of the Blood Moon.


Rom only starts attacking after the first teleportation and adds a few more attacks once he teleports the second time. Here are all the attacks you have to look out for:

  1. Boulder Barrage: Moves his head upwards and hurls multiple ice boulders at you.
    • Reaction: Pick a side and keep running until the boulders stop dropping.
  2. AOE Explosion: Raises his tail and a wind will engulf his surroundings leading up to an AOE explosion.
    • Reaction: Back off ASAP.
  3. Upward Boulders: The boss rolls over and summons boulders that shoot up from the ground around the radius of the boss.
    • Reaction: As soon as you see him roll over and the ground around him starts glowing, start running back. You can position yourself safely in the gaps between the glowing bits to bypass the attack, but backing away is harder to pull off, but it is advised.
  4. Body Slam: Wildly flails his head and tail to hit you with it. He only performs this attack after the second teleportation.
    • Reaction: Position yourself in his middle section, away from the head and tail, and evade when he starts flailing.

Rewards for Defeating Rom & Triggering the Blood Moon

Blood Moon
The Blood Moon in all its Glory.

Besides the 24,860 Blood Echoes you’ll receive from beating Rom, you’ll also get one Kin Coldblood 12. Consuming this item will grant you an additional 20,000 Blood Echoes. Other than that, killing Rom, the Vacuous Spider triggers the Blood Moon and changes the world quite drastically.

Here are all the noticeable changes you’ll see once the Blood Moon starts (thanks to Redditor Firelink-Hermit for the list):

  • The moon changes into Blood Moon (save for some areas)
  • Music changes in Hunter’s Dream
  • The Doll has different dialogues if you talk to her.
  • Impostor Doctor can now be found writhing on top of the table on the upper floor of Iosefka’s Clinic. (You can take a Third Umbilical Cord by killing her)
  • Gilbert turns into a beast. (He’s the NPC near the Central Yharnam Lamp)
  • Yharnamites stop responding when you knock on their door or approach their window (select NPCs cannot be sent to Iosefka’s Clinic or the Chapel); instead, either have no response at all, or you get some crazed gurgling noises.
  • Amygdalas are now permanently visible over Cathedral Ward.
  • Hypogean Gaol (and Grand Cathedral) lantern is no longer accessible.
  • Eileen and the Bloody Crow can be found at the Grand Cathedral
  • Kidnappers (aka Snatchers or “Bag Bois”) in Cathedral Ward and Yahar’gul die
  • Transformed Man (aka Suspicious Beggar or Abhorrent Beast) disappears from his Forbidden Woods location if you missed him or didn’t send him to Oedon Chapel or Iosefka’s Clinic.
  • Yahar’gul’s difficulty dials up from “Trick or Treat” to “You Died”
  • Father Gascoigne’s 2nd Daughter appears in the same window as the first one.

This is how you can easily defeat Rom in Bloodborne. We might be missing a thing or two about the Blood Moon since the Bloodborne community is still finding secrets in the game to this day. So, check other forums if you are interested in more details.

But, it is safe to say that Bloodborne’s difficulty amps up quite significantly once the Blood Moon is triggered. Well, have fun, good hunter, and be safe!