Even nearly a decade after its release, The Inferno remains one of Old School RuneScape's most brutal challenges. Sixty-nine waves of escalating punishment stand between players and victory, and at the very end waits the towering, fire-wreathed final boss: TzKal-Zuk.

In gameplay, Zuk is already terrifying. In lore, he's even worse.

The Inferno wasn't originally meant to be a simple trial. It was an ancient incubation chamber, uncovered through Thzaar experimentation in the pursuit of forgotten power. Realizing the chamber's potential,with cheap RuneScape gold,they placed the eggs of every Fight Cave creature inside it. What emerged were twisted, volatile versions of familiar monsters. But this place wasn't just a laboratory—it was also a prison.

That prison held Zuk.

According to the lore, he rose above all the other infernal creatures, bending them to his will and claiming dominion over the entire gauntlet. Which raises a perfect, nerdy question: could Zuk actually conquer the Inferno himself? Could he defeat all 68 waves and earn his right to stand as the ruler of the 69th?

To find out, a full simulation was run, pitting TzKal-Zuk against the Inferno from wave one onward.

The Inferno vs. The Fight Cave: Same Idea, Far More Pain

At its core, the Inferno follows the same structure as the Fight Cave: waves of enemies, each adding new threats, building all the way up to Jad—three of them, in fact. The difference is that Inferno monsters are far stronger and come with nasty new tricks.

Take the blob (Jal-Ak) for example. In the Inferno, it's over triple its Fight Cave combat level. It can attack with all three combat styles and splits into three smaller blobs instead of two—each using a different style. These things aren't just annoying; they're relentless chip damage machines.

Then there's Zuk's signature mechanic: the moving shield. If the shield is between Zuk and his target when he starts an attack, the attack is completely blocked. That's a huge problem when your attack speed is a painfully slow 10 ticks. Over the course of the run, this shield ends up sabotaging Zuk again and again, eating crucial hits at the worst possible times.

The Inferno pillars also change the dynamic. Players rely on them to safespot and control waves, but Zuk doesn't care—he just stands there and tanks everything. That also means he ignores nibblers, the small monsters that normally chew down the pillars. Since Zuk doesn't need cover, they're a low priority… but they still add to the total damage pressure over time.

The First Attempt: No Sets, Just Raw Power

To get a baseline for Zuk's strength, the first run gave him only his unique healers—no extra “set” spawns to help him. The goal was simple: see how far pure boss stats could carry him.

Early waves were trivial. Zuk casually erased bats, blobs, and low-tier monsters without much trouble. Even the meleeer, Jal-ImKot, was irrelevant since Zuk can't be reached by melee anyway.

The real problems started when rangers and majors entered the mix.

By wave 18, the first ranger (Jal-Zil) showed up—level 370, max hit 46—and while Zuk could one-shot it, the incoming damage started to stack up. Things got ugly fast. By wave 31, Zuk was getting absolutely shredded by combined ranger pressure and unlucky shield blocks. In one wave alone, he took over 250 damage, more than 20% of his total HP, just from sustained punishment and missed attacks.

Wave 35 introduced the first major (Jal-Zek), a level 490 monster with a max hit of 70 and the ability to respawn fallen enemies at half HP. That's where Zuk was finally forced to spawn his healers just to stay alive. They pushed him back over 1,000 HP—but once they were gone, he was on his own again.

To put the scale of this challenge in perspective: if you count every monster and every nibbler across the Inferno, there are 535 total enemies with a combined 25,730 HP. That's an absurd endurance test, even for a boss.

Zuk kept pushing forward, barely scraping by wave after wave, and somehow limped into wave 50 with just 43 HP left. Against all odds, he survived one more wave—but wave 51 was the end. Without support, raw stats just weren't enough.

Full Power: Sets, Jad, and Total Chaos

Lore-wise, Zuk isn't supposed to fight alone. He can spawn support sets—each containing a major and a ranger—and once he drops low enough, he can even spawn a Jad. So the second phase of testing turned everything on.

With sets spawning every 45 seconds and then every 3.5 minutes, plus a Jad entering the fight after Zuk hit 480 HP, the battlefield became absolute chaos.

There were moments of brilliance: Zuk timing set spawns perfectly to pull aggro, healers restoring him back to full, and waves getting deleted in seconds by massive hits. When things lined up, he looked unstoppable—this was the lore-accurate tyrant of the Inferno.

He pushed further. Much further.

This time, Zuk broke past his previous limit and reached the late 60s. Again and again, he made it to wave 68—but triple Jad proved to be a brick wall. Hundreds of attempts were simulated. For days, the runs kept coming. About a third of them reached wave 68, and almost all of them died there.

It was brutal. Frustrating. Very on-brand for RuneScape.

The Perfect Run

And then… it happened.

One run where everything clicked.

Zuk was a monster: one-shotting enemies, soaking hits, using set spawns at exactly the right moments to control aggro. He entered wave 68 with 855 HP and a major at his side. The chaos erupted. Fire, hitsplats, respawns,with OSRS gold,and pressure from every direction.

And this time—he survived.

Wave 68 fell.

TzKal-Zuk finally proved it. He didn't just rule the Inferno by lore—he earned it in practice. He conquered all 68 waves and secured his throne as the true final boss of wave 69.

Final Thoughts

This simulation showed just how absurd the Inferno really is. Even its own final boss struggles to survive the gauntlet designed to lead up to him. Without help, Zuk falls short. With full power and enough attempts, he can—just barely—claim victory.

Which, honestly, feels perfectly RuneSccape.

If even Zuk has to grind hundreds of attempts to win… what chance did the rest of us ever have?