OSRS Boss Gear & Inventories

Zulrah

Combat level 725 · 500 hitpoints

The classic gear-check money boss. Zulrah cycles three forms (green, blue tanzanite and red crimson) in fixed rotations. The best setup uses both Ranged and Magic to hit each form's weakness, though a strong enough single weapon can now carry the whole fight.

Requirements

• Regicide (partial) for Zul-Andra
• 75+ Ranged and 75+ Magic recommended
• 43+ Prayer (70+ for Rigour/Augury)

Pointers

• Weaknesses, which are NOT the same as what it attacks with: green is weak to MAGIC, red/crimson is weak to MAGIC, blue/tanzanite is weak to RANGED. Magic performs badly on tanzanite specifically.
• Single-style is now viable at the top end: a Twisted bow or Bow of faerdhinen kills it without magic switches, and a Noxious halberd can melee the whole fight.
• Green form = attacks with RANGED, so Protect from Missiles and hit it with MAGIC. Blue form = attacks with MAGIC, so Protect from Magic and hit it with RANGED.
• Red (melee) form spawns snakelings. Move away and keep attacking Zulrah, they die on their own when it submerges.
• The venom clouds are the real killer. Never end a tick standing in one; step to the marked safe tile as it submerges.
• Anti-venom+ is not optional. Zulrah applies venom, which ignores normal antipoison.
• Learn ONE rotation from a Zulrah helper/plugin before you go. Blind kills are how people lose gear.
• Bring a Serpentine helm if you have one. It makes you venom-immune and removes the biggest failure mode.

What the sim brings here

Every worn slot and every inventory row below is the combat simulation's own output, at the style it ranks fastest for each account tier. Each line carries the channel that chose it: sim means the model solved it, and inherited means the value came through from the hand-authored loadout the solver starts from. Riding through a generator does not make a value derived, so those are marked rather than presented as the model's answer. A line marked unattributed carries a channel the model's own vocabulary no longer declares, so no word is put on it at all rather than one being read off the channel's spelling. Where the model has not answered a row, its own refusal is printed instead; where it has answered a row it doubts, the answer is printed with the doubt attached rather than withheld.

What each of those badges means

• derived:ascent (sim): an accepted coordinate-ascent move: betterThan() preferred this candidate over the incumbent under the row objective and band. The weapon+ammo+shield pairing and the crystal set arrive here too, because both are offered to the same acceptance test.
• derived:cheapestEqual (sim): cheapestOfEquals(): at budget, an exactly-tied cheaper item replaced the one in this slot. It changes the price and, by construction, not the score.
• derived:composed (sim): balanceInventory() sized this row from the derived supply menu. The menu enumerates CONSUMABLES and narrows by style, tier and price; it is not the authored bag.
• derived:empty (sim): the finished loadout leaves this slot EMPTY, and that is an ANSWER rather than a gap: a two-handed weapon forfeits the shield and a weapon that stores its own ammunition frees the ammo slot. Recorded so a null slot is never read as unprovenanced.
• derived:obtainable (sim): canonicaliseObtainable(): the finished loadout named a variant the model cannot state a route to, and this pass swapped it for the obtainable equal.
• derived:required (sim): requiredUtilities(): the fight was priced with and without the item and carrying it lowers damage taken. No per-boss table.
• derived:seedWeapon (sim): the weapon the ascent BEGAN from, taken off the dps-ranked weapon shortlist, or the forced weapon of a multi-start seed. Never off a start loadout.
• derived:travel (sim): travelPlan(): the way IN, ranked out of the derived transport graph against this account's own unlocks, rather than copied from whatever a human typed. The way OUT is a separate channel (`ruled:escape`) because it is a typed choice, not a ranking.
• ruled:escape (ruled): escapeLeg(): the way OUT, taken from the typed per-tier table ESCAPE_PLAN and judged against the account, with nothing substituted and no fallback ladder. The ACCOUNT CHECK is a derivation; the CHOICE of item is not, so this is not a `derived:` channel. ESCAPE_PLAN carries no attributedTo field (PROVENANCE_BACKLOG: silent-and-unattributed), so this channel does not claim one either.

Zulrah strategies on the OSRS Wiki