Depth 4 Dungeons Guide

From Idling To Rule The Gods

Depth 4 Dungeons are substantially more difficult than previous depths. Relatively little is known about how to tackle them. This page has some information that may help.


The suggested starting point for a depth 4 dungeon team, according to the game's developer, is Dungeon Level 220, Class Level 60, 150k Growth, and a mix of tier 3 and tier 4 equipment. Obviously this is not a firm requirement, nor is it sufficient for the boss rooms (see below).

Each depth 4 dungeon has 2 regular (preventable) traps, 1 unpreventable trap, and 2 events. The events are consistent across all dungeons. Passing the first event requires a key which matches the dungeon's element, and if passed, gives 1 crafting bar of the dungeon's element (e.g. Titanium Bar) and 30 god power, and increases the monster attack and health by 50%. Passing the second event requires all 6 team members to match the dungeon's element, and gives one tier 4 crafting material (e.g. Mythril), 5*(1 + 0.1*difficulty) growth in each stat to each pet in the party, 25% more experience, and increases monster attack and health by 50%.

The keys for the first event may be crafted by an Alchemist from the stones found in the matching element's Infinity Tower, or looted from the depth 4 boss.

Speaking of which: each depth 4 dungeon also has a boss room, which occurs as the 60th room. Reaching it requires that all NRDC have been completed, and needs a full 12-hour expedition. The boss room is significantly more challenging than regular depth 4 rooms.

Alchemists may also craft Nanotraps and Freezing Bombs. Nanotraps act against the Nanobot monsters in the depth 4 Scrapyard. Freezing Bombs reduce the speed of depth 4 monsters by 50%, but may not be used together with Nanotraps or keys.

General Tips

All of your team's equipment should be at minimum fully maxed tier 3 (SSS +20 with 20 enchantment and a level 10+ gem). A scattering of tier 4 gear will help. Due to the large amount of damage you may receive, a higher than average number of water gems is strongly advised for most pets.

Most teams will have a small number of damage-dealing pets, but these pets need to be exemplary at their craft. A good damage-dealing pet:

  • Should have a class matching its evolution bonus, for the extra damage (no wildcards). The higher the evolution bonus, the better. There's one exception to this rule -- see Volcano.
  • Should have an appropriate element for dealing damage in the chosen dungeon (e.g. Water pet in Volcano), unless you're setting up for the matching element event.
  • Should have full tier 4 gear if possible.

Pets that have a special dungeon ability, such as Hourglass's enemy speed debuff or Archer's double shots, may be extremely helpful in some cases.

The pets who are acting in a supporting role (Defenders, Supporters and Rogues, or occasionally a Blacksmith) have less strict requirements. Usually they just need to survive. Defenders should have neutral gear with earth and water gems. For Supporters and Rogues, the equipment choices can be more complicated.

Supporters and Rogues will typically use knives, as Supporters will attack when nobody needs healing. Note that a maxed tier 3 knife reduces a monster's defense by 1% per hit. A tier 4 knife that's not SSS quality will delevel **less than** 1%. If your tier 4 knives aren't all SSS quality, you'll need to balance the knife's stats against its deleveling power.

Supporters may need to have their speed adjusted through trial and error. Ideally, you want them to act *after* monsters have done their first attacks, then again after a second round of monster attacks, and so on. Since monster speeds vary, it's impossible to find a perfect Supporter speed, so just do your best.

When attempting a depth 4 dungeon for the first time, you will probably be unable to defeat the boss room, or any room that gains 50% monster stats from passing the events. Therefore, it's unwise to bring keys or to use a single-element team, or to allow a team to remain in depth 4 for a full 60 rooms, until you're stronger. You may also need to bring Freezing Bombs or Nanotraps, depending on the strength of your team and which dungeon you're attempting.

Having large Dojo dungeon buffs will also help.

Single-element Teams

Making the transition to a single-element team is actually easier than it sounds. Having all your pets match the dungeon's element greatly reduces the damage they take (apart from Scrapyard, or off-element or neutral monsters in other dungeons). This allows you to shift equipment to favor attack/speed a bit more.

With your pets mostly acting as tanks, you'll still need at least one good damage dealer -- a Mage or Assassin. Building up your best attacking pet's levels (via ego swords, free XP, etc.) should be considered a prerequisite step. Aim for dungeon level 300. Everyone who's not a dedicated damage dealer will be doing smaller amounts of damage. Therefore, knives should be your go-to weapon of choice for Supporters and Rogues, and possibly even Defenders, to help weaken the enemies for your big damage dealer(s).

Of special note here, the Volcano dungeon at difficulty 1 or higher reduces your pets' fire element over time. This will obliterate your ability to damage the enemies, if your big damage dealer is a fire pet. The trick, then, is to use either Chameleon (with its element set to neutral or water) or Tödlicher Löffel as your damage dealer. Their special ability to act as the needed (fire) element for events is essentially required here.

Next, we'll look at each dungeon.


The unpreventable trap is a Railgun that shoots one random pet for 20k damage (more at increased difficulty levels) which ignores defense. A pet hit by the Railgun, even if it survives, can't be revived by phoenix feathers in this room.

Due to the Railgun trap, pet Health is critically important. You'll want all pets to have at least 30k Health for difficulty 0. Use water gems, or metal/earth equipment, as needed to ensure survival.

One of the monsters is a Nanobot which can replicate itself, unless prevented by Nanotraps. Nanotraps prevent the use of Freezing Bombs. There's also a monster which can Heal.

The good news is that once you've taken all of the above into account, the monsters aren't terribly strong. Sure, they're neutral, so you want to avoid having negative elements, but if you're going with an all-neutral or mostly-neutral team here, elemental resistance holes shouldn't be a major concern.

Sample all-neutral team: Dog (Defender), Carno (Assassin), Archer (Assassin), Black Hole Chan (Mage), Tanuki (Supporter), Ghost (Rogue). Other variants are possible (e.g. Gray kid 2 or Anything can be used in place of whatever pet you like here).

If you can't handle an all-neutral team yet, Salamander is a good choice for Supporter, since it gives an extra burst of healing at the start of every turn, right after the Railgun fires.

Water Temple

The unpreventable trap is a Lethal Poison which inflicts stacking poison to pets every turn, causing pets to receive 1.5 x stacks% max hp damage each action. It cannot be removed, except by completing the room, at which point it goes away by itself. Do not question the magic.

The Deep Sea Undine monster can inflict a Frozen Aura, which does additional damage per turn, and can also Heal.

The key to this dungeon is dealing enough damage to defeat the monsters (including surpassing the Deep Sea Undine's powerful healing. particularly when there are 2 or more of them) before the Lethal Poison reaches high enough damage to kill your team.

Starter team: 2 Defenders, 2 Supporters, 2 damage dealers (token-improved Rabbit or another Mage or Assassin).

The token-improved Rabbit is the top pick due to its element (Water enemies have low resistance against Earth) and the amount of damage it can unleash with full tier 4 Earth gear with Fire gems. Equipping it as a full glass cannon (no water gems) works due to the 2 Defenders, and the natural HP bonus of Earth gear.

It might be feasible to replace one damage dealer and/or one Supporter with a Rogue, once your team is stronger.

Sample all-Water team: Whale (Defender), Chameleon (Neutral, Defender), Clam (Rogue), Undine (Rogue), Frog (Supporter), Witch (Mage). Chameleon counts as Water for the event. You could use Gray kid 2 as a second Water Defender if needed. Witch is the primary damage dealer, but Clam and Undine act as secondary damage dealers with good equipment, levels and growth. Note that this team fails the depth 2 Hidden Library event (which needs 2 Supporters), so it may lose a small number of rooms per trip. This makes it unsuitable for fighting the depth 4 bosses.


The unpreventable trap is Oilburn, which deals 5% of max HP damage per turn, and reduces pets' Fire element by 100 * difficulty level per turn.

This dungeon also features the Hell Rabbit, which can replicate itself (a Mage is helpful), the regenerating Obsidian Giant (fully heals after each hit, so you have to one-shot it), and the Infernal Salamander with a Healing Aura.

Tödlicher Löffel and the neutral Chameleon don't lose damage capability due to the Fire element reduction of Oilburn, while still counting as a Fire element pet for purposes of the event. This only matters if you're attempting to run D4-1 or higher with an all-Fire team.

Finally, this particular dungeon is noteworthy for the extra rooms that you can receive. Stopping at room 59 to avoid the boss fight will not be viable. You'll need to be boss-ready before attempting this one.

Starter team: Defender, Supporter, Rogue, Blacksmith, Assassin, Mage (Slime or Witch). Your Mage and Assassin will both need to be competent at their respective jobs (cleaning up summons, and one-shotting Giants). Todlicher or Chameleon can be swapped in when you're ready to go for an all-Fire team.


The unpreventable trap is the Gravity Bomb, which reduces all pets' speed by 99%. Effectively, every pet will only be able to act once per turn, unless you have ludicrous speed.

There is also a monster with Heal.

With freezing bombs to reduce the speed damage you take, and a really good damage dealer (Vesuvius qualifies), you can begin to make progress here. You'll also want to boost pet HP a bit, because the enemies will get all their attacks in before you can act. Even with double Defenders, surviving that onslaught will require a bit of preparation. 15k HP may be enough for your Mages/Rogues at difficulty 0 with bombs and no events. It definitely won't suffice without bombs.

Sample team: 2 Defenders, 2 Rogues, 1 Supporter, 1 Mage.


The Forest is considered the easiest depth 4 dungeon, and is where most players will begin. In addition to being the easiest to survive, there's considerable incentive to succeed here, due to the potentially larger amounts of tier 2 and tier 3 wood that can be obtained. Special wood and magic wood are frequently needed for upgrading the Tavern or Dojo, or for crafting. A depth 4 difficulty 0 team with 2 Rogues can obtain slightly more special wood than a depth 3 difficulty 10 team with 3 Rogues. However, if you're currently farming D3-10 with more than 3 Rogues, you might wish to remain with that setup until you can handle more than just D4-0 without events or bosses.

Torches and Antidotes will prevent the regular traps here; you may skip the Antidotes if you need the extra carry slots, as the Poison trap is quite weak. The unpreventable trap is a Stungun which randomly stuns one pet per turn. This stun lasts for 3 actions.

The most significant monster in this dungeon is the Cosmic Gnome, which has 99,999 defense and 200 HP, and is immune to speed damage and defense deleveling by knives. Due to its insanely high defense, it will take 1 damage from almost any attack. The intended way to defeat this monster is with a Mage, dealing multiple attacks per action.

The fact that the Cosmic Gnome is the most significant monster is what makes this the easiest depth 4 dungeon. There are no summoners, no healers, no infinitely increasing poison damage, etc. There are monsters that can deal a lot of damage, but that's true everywhere. You simply need to survive the incoming damage, and deal enough damage of your own to win within the 50 turn limit.

Starter team: 2 Defenders, 2 Rogues (or 1 Rogue + Hourglass), 1 Supporter (not Hourglass), 1 Mage.

Alternative team: 1 Defender, 2 Rogues, 1 Mage, 1 Supporter, 1 Assassin (or second Mage).

In both of the above teams, the squishy Mage may need some Earth gear and/or Water gems to improve survivability, or else you'll burn through phoenix feathers. When increasing the difficulty above 0-1, the second Mage may be needed against rooms with multiple Cosmic Gnomes.

Sample all-earth team: Gnome (Defender), Turtle (Defender), Lucky Coin (Assassin), Panda (Supporter), token-improved Rabbit (Mage), wildcard Rogue. This team sacrifices multiple-Rogue wood income for durability, so it may not be a good choice before your Tavern and Dojo are fully upgraded.