Mastering the Rat King Boss Fight in The Last of Us Part II Remastered
When I first sat down with The Last of Us Part II Remastered on PlayStation 5, I thought I knew what to expect. I had played the original on PS4, survived Grounded difficulty more times than I care to count, and told myself that a remaster was just a prettier version of the same pain. Then I reached the Rat King boss fight in the Aquarium, and everything I thought I knew about pressure and resource management evaporated. This fight is not just a difficulty spike. It is a brutal exam on everything the game has taught you so far, and on Grounded difficulty with a no damage run, it becomes a masterclass in precision and patience.
The encounter takes place in the Aquarium's dimly lit lower levels, a space that is both claustrophobic and strangely beautiful in 4K HDR. Naughty Dog designed this boss arena with a specific rhythm in mind. The Rat King boss, a hulking infected creature fused with a living colony of rats, moves in ways that punish hesitation and reward careful observation. If you are attempting a no damage run, you learn quickly that this is not a fight you can brute force. Every swing of its claws and every surge of rats must be accounted for, or you restart from the last checkpoint.
Understanding the Rat King's Behavior
What makes the Rat King boss fight so memorable is how it forces you to use the environment. The Aquarium is not just a pretty backdrop. Its glass tanks, narrow corridors, and elevated platforms give you options, but they also funnel the Rat King into positions that can trap you. On Grounded difficulty, one mistake is all it takes. I have died more times in this room than in any other encounter in the entire game, and each death taught me something new about the boss's attack patterns.
The Rat King has two primary phases. In the first, it moves slowly and relies on sweeping melee attacks that can knock you down if you are not blocking or dodging at the right moment. It also summons waves of smaller infected rats that swarm from the sides. These smaller creatures are easy to dispatch individually, but they create chaos when you are trying to focus on the main boss. The key is to keep moving, use the Aquarium's pillars for cover, and never stay in one spot long enough for the Rat King to corner you.
Once you reduce its health by about half, the Rat King enters a second phase where it becomes faster and more aggressive. It starts using a charge attack that can cross the arena in less than a second, and it begins to climb walls to reposition itself. This is where the fight transforms from a brawl into a tactical puzzle. You cannot rely on the same strategies from the first phase. You have to read its tells, anticipate its movements, and punish it only when you have a clear opening.
Grounded Difficulty and the No Damage Run
Playing on Grounded difficulty is not for everyone, and I respect that. The game's default settings already provide a challenging experience. But for those who want to test the limits of The Last of Us Part II Remastered, Grounded is the only way to go. Resources are scarce, enemy AI is more aggressive, and your health bar is thin. A single hit from the Rat King can end a run that took hours to build. That is why the no damage run is such a specific goal. It is not about being good at the game. It is about being perfect, and perfection in this fight requires a deep understanding of every tool at your disposal.
I remember the first time I attempted a no damage run against the Rat King. I had spent the entire game collecting every collectible along the way, and I had upgraded Abby Anderson's skills to their maximum. I thought I was ready. I walked into the boss arena confident, and within thirty seconds, a rat swarm clipped me from behind. That was the run over. The frustration was real, but it also taught me that the no damage run is as much about mental discipline as it is about mechanical skill. You have to accept that you will fail, and each failure teaches you something new about the fight.
Weapons and Items That Make a Difference
One of the most important lessons I learned is that your loadout before the fight matters enormously. If you have been saving your best items for a rainy day, this is that day. The chainsaw, which appears earlier in the game, is a powerful tool here if you still have fuel. It can stagger the Rat King and clear out the smaller rats quickly, but it also leaves you vulnerable during the revving animation. I have found that a combination of the hunting pistol with explosive rounds and a fully upgraded melee weapon gives the best balance of range and safety.
Another critical item is the health kit. On Grounded difficulty, health kits are rare, and you should not waste them on minor scratches. Save them for moments when the Rat King's attack forces a trade. Even in a no damage run, you might need to heal if you make a mistake, but the goal is to avoid that entirely. I have seen players use smoke bombs to break line of sight and reposition. That works, but it takes practice to time it correctly. The Rat King's AI is smart, and it will track you through smoke if you are not quiet.
The Role of Collectibles and Exploration
One aspect of The Last of Us Part II Remastered that I appreciate is how the collectibles tie into the gameplay. Finding all the artifacts, trading cards, and journal entries is not just for completionists. It also gives you context about the world and the characters. In the Aquarium area, there are several collectibles that tell the story of what happened to the WLF and the Seraphite factions before Ellie Williams and Abby Anderson arrived. These small details make the world feel lived in, and they reward exploration in a way that directly benefits your run.
For example, one collectible in a side room near the boss arena reveals that the Firefly group had a hidden cache of supplies in the area. If you find it, you get extra ammo and a health kit. That might not seem like much, but on Grounded difficulty, every bullet counts. Another collectible mentions the Clicker, the signal device used by the WLF, and hints at a secret passage that lets you bypass a particularly dangerous section of the Aquarium. These discoveries do not make the Rat King boss fight easy, but they give you a fighting chance.
Visual and Audio Design in 4K HDR
Playing The Last of Us Part II Remastered on PlayStation 5 with HDR10 support changes how you experience the Rat King boss fight. The Aquarium was already a visually striking location, but in 4K HDR, the contrast between the dark water and the bright emergency lights creates a tension that is palpable. The Rat King's body, a mass of writhing rats, looks grotesque in a way that the original hardware could not fully render. Every detail, from the wet floor to the reflections in the glass, adds to the immersion.
The audio design is equally important. The sound of the Rat King's footsteps echoes through the Aquarium's halls, giving you a directional cue before you see it. The squeaking of the rats, the splash of water, and the heavy breathing of the infected creature all combine to create a soundscape that keeps you on edge. I have completed this fight dozens of times, and I still feel a chill when I hear the boss's roar. That is the mark of great design.
Final Thoughts on the Rat King Boss Fight
The Rat King boss fight in The Last of Us Part II Remastered is a defining moment for anyone playing on Grounded difficulty. It tests your patience, your resource management, and your ability to read enemy patterns under pressure. For players aiming for a no damage run, it is a crucible that separates determination from luck. I have spent countless hours in that boss arena, learning its rhythms and refining my approach. Each attempt brought me closer to understanding not just the fight, but the game itself.
If you are preparing for this encounter, my advice is to take your time. Explore the Aquarium thoroughly for collectibles. Study the Rat King's movements in the early phase. Do not rush into the second phase without a plan. And above all, accept that you will fail. That is not a weakness. It is the path to mastery. The Rat King boss fight is not just an obstacle. It is a teacher, and if you listen, it will make you a better player.