The Kalphite King, formerly dubbed the "Toughest Boss in RuneScape history", is a boss monster who can be found in the Exiled Kalphite Hive. At a combat level of 2500, it is currently the third strongest monster outside Dungeoneering, after Vorago, Araxxi, and is tied with Araxxor.
The Kalphite King was first mentioned at RuneFest2011 in Mod Mark's RuneScape 2012 speech. The Kalphite King is the only monster in the game that can drop the Drygorelongsword, mace and rapier, along with their off-hand versions, powerful melee weapons that require 90 attack in order to wield.
The fight with the Kalphite King is a challenge that requires players to be adept with the action bar system and changes with the introduction of the Evolution of Combat. The King is also able to summon marauders to his aid.
The Kalphite King will not allow dwarf multicannons to be set up. Dreadnips and dominion mines can be used, however the latter will not do any damage. Players may leave any time they wish, by teleporting, dying or leaving by the slope they used to enter the lair.
Upon first entering the hive, there will be a blocked tunnel that can be cleared to create a shortcut (that required level 23 Agility to use). This tunnel only needs to be cleared once. Click on the entrance near the tunnel, after which you can make or join a player's instance.
After a player enters the lair, the King will spawn and the fight will begin.
Note: All drops are split amongst a selection of players when using CoinShare/LootShare. Sharks are split into groups of 5, rune bars split into groups of 8, onyx bolts split into groups of 40, black dragonhide split into groups of 20, super restores being split into groups of 4, and earth talismans split into groups of 10.
The Kalphite King was heavily patched with the patch notes of 19 June 2013. The King, after the patch notes which affected weapon accuracy, has had his Defence lowered drastically so players could hit him more. However, the King is also able to hit much harder than before on players, and his minions that spawn are stronger and more accurate than before.
Assuming Kalphites indeed do follow the social structures of real life insects, It is possible that the Kalphite king might technically be an abnormally powerful Kalphite Guardian and not the literal 'King' of the Exiled Kalphite Hive.
When the Kalphite King uses its instant-kill attack, if Anticipate is used before this attack it will not be removed, although players will still be stunned. This does not work with other abilities as they are removed by the attack.
For a short time after the Kalphite King was released, using binds and stuns constantly prevented the King from changing combat styles, attacking, and summoning marauders. This was quickly fixed in a hidden update.
With the release of Legacy Mode, the Kalphite King will spawn in any combat style. Prior to this, it always spawned in melee form. The same update also reduced the slayer experience given upon death; prior to Legacy Mode the King gave 15,853 slayer experience rather than 3,963 slayer experience.
A hidden update to the King turned the instance to last for 60 minutes, after which no more Kalphite Kings will spawn. Players who leave the King's lair (manually leaving via slope), will also have to wait a few seconds before they can make or enter another instance.
The Kalphite King is one of the few bosses in RuneScape that aren't stun-immune.