The Royal Rat Authority is fought in the Doors of Pharros, just past the second bonfire. The fight looks easy with four small rats in the room; once the small rats are engaged, a giant rat will appear shortly after.
There are no NPCs that can be summoned as a phantom for this fight. It seems that other players can't be summoned to assist as well. This is probably due to the fact that this area is a PvP area designed to forcibly take the player into another players world.
Once you enter the fog door, the boss fight does not start immediately. This gives the player some time to devise a plan to take on the first phase. Whatever choice the player makes, it needs to be acted on quickly once the rats are aggro'd because the big rat will soon jump down and join the fight. The small rats can inflict Toxic and stunlock the player while the Rat Authority can take the player out with one attack. Minus the small rats, the fight is reminiscent of Sif from the previous Dark Souls.
There are a couple of ways to tackle this boss and all ways go to killing all four of the smaller rats immediately.
- Halberd - Run up to the rats, just close enough to aggro them, then run back towards the entrance. Turn around and do the sprinting normal attack to spin and kill all 4 of them.
- Sorcery - Sorceries with large areas of effect like Soul Vortex, Soul Spear Barrage and Soul Shower will be useful. Homing Soulmass is useful as a secondary line of defense. Aggro them and cast the sorcery when they can all be hit with one cast.
- Pyromancy - The pyromancy to use is Lingering Flame, sold by Straid. Set up the Flames just outside of the little rats' aggro range. Cast as many times as needed. Once the flames are in place, aggro the rats and run back behind the flames. The rats will trigger the Flames and die. With luck, one can deal massive damage on the boss as well. Casting Flame Swathe along with Lingering Flame will end the fight rather quickly.
- Miracle - The most essential miracle for the first part of the strategy is Lightning Spear . This is used to target each of the smaller rats from across the arena and take them out before they can harm you or infect you with toxic damage. In order to do this, one must first target the front left one. When the spear is thrown, do not wait to see if it kills the rat. Even with a low Faith stat, the base damage will kill them. If the player does not hesitate between throws, all the rats will be dead before the giant rat has a chance to attack. Alternatively, one can lure all the small rats to them, and cast Soul Appease to defeat them instantly. This will damage the big rat as well if you are in range.
- Bow - If your bow does over 200 damage, snipe the closest rat. Then lock onto the left-most rat and shoot. Before your arrow connects, shift to the next one to the right, shoot, and repeat for the right-most rat. The Short Bow (Dark Souls II) and Composite Bow (Dark Souls II) work the best for this.
Phase 2: The big rat is very simple, but can be annoying. Its attacks are similar to Sif's with some differences. What one wants to do is stand under him as it has a spinning attack that will cause heavy damage and drain the stamina bar quite rapidly if blocked. It is possible to run under him and attack his left hind leg as he does his front paw swipes. Use caution as the Authority can follow-up quickly with additional swipes. Circling to his right will help to avoid most of his attacks. He will jump away after a little bit and may do a headbutt, this attack can easily be blocked if the player has a shield with high stability. It is advisable to roll away or backstep when he is at critical health, as he will vomit an acid substance that will degrade your equipment very quickly and potentially break it.
Royal Rat Authority Soul
- Killing this boss is one of the requirements to buy the Flying Feline Boots from Sweet Shalquoir. The other boss needed to be killed is the Royal Rat Vanguard.
- All of the rats, including the Royal Rat Authority, are weak to fire.
- The lesser rats can apply toxic to the player, but the big rat will not. If the player gets Toxic they should prioritize finishing off the small rats and then immediately healing while staying under/behind the large rats. A few swigs of the Estus Flask should suffice.
- All of the lesser rats can be killed in one hit from a Lingering Flame with an un-upgraded pyromancy flame.
- If the player's pyromancy is good enough, it's very easy to use Lingering Flame on the left side of the room and bait the smaller ones to chase the player so the boss lands on the flames. Doing so will cost him 3/4 of his health if the pyromancy hand is +10.
- The small rats have a chance to drop a Pharros' Lockstone when slain, making the Authority a great place to farm for lockstones.
- By using a Bonfire Ascetic on the Doors of Pharros bonfire, Ordeal's End, the Royal Rat Authority can be respawned.