Black pearl farming guide

The guide to black pearl farming. Stop wondering about how you are supposed to get them and finally rank up your town.

Target audience

This guide is written for game version 1.1.15.5. With the exception of the Fishing With Dynamite quest, it should work in previous published version.
Version 1.3 significantly altered early game balance. Pilfering mimics is a lot more difficult (the game became a lot more DPS oriented, not killing them and not being killed by them can be tricky) and portal orbs are a lot more common. Passive black pearl farming by running dungeons is a lot more viable now and pilfering mimics probably isn't needed.

This guide is mostly for early-ish game, when black pearls are a limiting factor. Certain assumptions are based on that.

The basics

Let's start with the basics. There are currently several sources of black pearls:

• All boss monsters (including these in super dungeons above F50)
  
• All metal monsters
  
• Mimics
  
• Fishing With Dynamite quest
  
• Fox Dungeon 2

There are some mechanics that affect black pearl farming. The important ones are:

• All sources of black pearls require entering dungeons (not necessarily clearing them though). Portal orbs are needed to get black pearls.
  
• Boss and metal monsters have black pearls as a rare drop.
  
• Mimics have black pearls as a common drop.
  
• The fishing with dynamite quest rewards 1 black pearl and requires defeating 10 boss devilfish. This reward isn't luck based and is guaranteed as long as you can clear any devilfish dungeon. It's usefulness is limited because it can't be increased and you need to clear a devilfish dungeon for it (this is a major limitation).
  
• Fox dungeon 2 rewards 1 black pearl per difficulty for the first completion in a WA. A pearl or 3 (diff 1+2) can be useful from that. It isn't the main source because this dungeon has no good rewards per clear and the numbers gained are too low to cover almost anything before ascending.
  
• All monster drops are affected by material multiplier mist - use it. I will assume you always use it when farming black pearls.
  
• Rare drop modifiers affect boss and metal monsters (equipment, trapper research, area mission milestones).
  
• Common drop modifiers (slime bank) affect mimics.
  
• Pilfer can be used to get a common drop from a monster, gets black pearls from mimics (and only from them).
  
• Pilfer is affected by material multiplier mist and it has its own success rate independent on base drop rate.
  
• Each monster can be pilfered only once (at least as far as I can tell).
  
• Each treasure chest has a 20% chance of being a mimic (statistical observation after millions opened chests).
  
• Treasure chest drop chance is 0.5% + 0.1% treasure hunter level (0.5% before ascending) from each defeated monster. This means 0.1% + 0.02% per treasure hunter level mimic spawn rate.
  
• Each monster has a 0.05% + 0.025% per metal chaser level chance of being a metal variant (0.05% before ascending).
  
• This means that, as long as you open all chests, mimics are more common than metals before ascending.
  
• Common drop chance is usually a lot higher than rare drop chance.

The active approach

This is the most effective way to get black pearls in terms of black pearls per portal orb and game time. The premise is actively using the Pilfer skill on mimics to get black pearls from them.

The setup:

• Unlocked Thief with Pilfer skill (steal chance increases at levels 60, 100, 150, 250 and is 5/10/15/25/50% depending on base level)
  
• A character that can either easily tank the monsters in the dungeon or can use short range skills to defeat them (sonic slash and similar).
  
• A dungeon you can barely clear - you need to defeat monsters to get chests, but you also need to be weak enough to not defeat the mimics with base attack and pilfer only. Clearing it isn't needed for black pearls, just make sure you don't die before you get the mimics.
  
• A way to switch from dungeon clearing skill set to pilfering skill set. This generally includes pause, skill loadouts or manually removing skills.

The execution:

• Prepare your skills etc. This includes properly leveling pilfer skill (you probably don't want thief to rebirth above T1 in the process). Find the right dungeon for you (if you have multiple candidates, pick the one with the highest monster count * chest drop chance value). Skill/equipment/buff selection can be used to adjust fighting power for the right dungeons.
  
• Make sure you aren't using the red fairy active pet - you want to open the chests at the right time, not when they appear.
  
• Clear some waves of the dungeon (more is better, but don't risk finishing the dungeon and leave yourself enough time to pilfer).
  
• You need treasure chests now. If there are none, just finish the dungeon and try again.
  
• Get your pilfering setup - unequip all dps improving skills other than base attack and pilfer, equip pilfer if it wasn't already equipped, equip material multiplier mist (if it isn't always equipped) and open all chests. Make sure you aren't killed by already present monsters in the process.
  
  • You should clear nonmimic monster first. Sonic slash and muscle inflation combo works well for this because of high dps and small range + AoE - you don't want to kill the mimics.
    
  • If you have pause, this part is easier, you pause, open chests and only if you see a mimic you go for mimic pilfering setup.
    
  • Without pause, you unequip everything with a long range/high AoE, open chests and, if there are mimics, get the skills to clear the nonmimics and then switch to pilfer for the mimic. If you can easily tank normal monsters, you might ignore them instead of killing them.
• If there are no mimics, reequip skills and continue the dungeon normally.
  
• Hit the mimics with pilfer until they either die or drop the black pearl. If there are multiple, try to keep track of each one and get a drop from each. Mimics have significantly more HP than most monsters so you should have some time for it.
  
• Reequip and clear/leave/fail the dungeon.

This approach isn't dependent on black pearl drop chance shown in bestiary, it is dependent on total monster population of the dungeon and treasure chest drop chance. Pilfer chance isn't that important if you can hit the mimic with it for long enough.

The passive approach

The passive approach is gaining pearls from mimics, boss and metal monsters as you clear dungeons. I consider the Fishing With Dynamite quest to belong there as well. With the exception of this quest, your drops are strictly luck based and unreliable with few dungeon clears.
Super dungeons contain boss monsters above F50 and these count as well, but you are unlikely to have material multiplier mist for them and you'd need many SD runs to get a decent stash. It has been already done by a player with a rather unusual playstyle (pushing SDs far with global/title quest dropped portal orbs and long WAs).
Efficiency is based on material multiplier mist, drop chances and the dungeon chosen. There are only 2 things you can significantly influence - rare material drop chance from equipment and the dungeon you run.
People reported good results when using Thief with only base attack and pilfer to directly attack enemies. Buffs like holy arch and haste are useful.

There's the list of the most important factors:

• The 90 area missions milestone with its 1.5 rare material drop multiplier is a part of mission milestones that happens when it happens.
  
• Rare material drop research should get a bunch of levels, but running it too much limits other more important research and there's only so far it can reasonably go.
  
  • Tanzanite gem ritual improves this research effect.
• Equipment with rare material drop chance can be stacked and swapped as needed. It can be found as an enchant, on Magicslime Baloon (from Area 8), Spider Stick (from area 7) and Treant Kokeshi (from area 6). The Treant one is probably too late for this.
  
• Common drop chance can be increased only by the Material Finder upgrade on the 3rd page of slime bank upgrades, if you have unlocked it. Its exponential price scaling means that it just goes up with slime coin cap/gain and you can't significantly influence it.
  
• Boss monsters and metal monsters are equal in terms of black pearl drops.
  
• Mimics are generally more effective because of common drop being higher than rare drop early on.
  
• Metal monsters can slow down dungeon clearing and metal chaser prestige upgrade might be better left at 0. This increases the significance of bosses and mimics. If you have area/dungeon prestige reset from epic store, ignore this point. Even at max level, metal population usually won't reach boss population.
  
• Treasure hunter upgrade increases mimic spawn rate. They can be a good black pearl source.
  
• Passive heroes in dungeons don't produce mimics, (This might have been fixed.)
  
• Monster composition of each 100 waves is roughly the same (similar number of common monsters, the same number of bosses). Prestiged dungeons are a good source of passive black pearls.
  
• The Fishing With Dynamite quest is mostly useless. Even if its reward wasn't so low (material multiplier mist makes in-dungeon drops far more effective), it requires clearing Devilfish dungeons that are notable for having no useful drops for farming.

Dungeon list

There's the observed population of dungeons (nonprestiged):

• Slime 1: 118 monsters, 0 bosses
  
• Slime 2: 154 monsters, 1 boss
  
• Slime 3: 230 monsters, 2 bosses
  
• Slime 4: 377 monsters, 5 bosses
  
• Magicslime 1: 120 monsters, 0 bosses
  
• Magicslime 2: 154 monsters, 1 boss
  
• Magicslime 3: 301 monsters, 2 bosses
  
• Magicslime 4: 472 monsters, 1 boss
  
• Magicslime 5: 472 monsters, 1 boss
  
• Magicslime 6: 472 monsters, 1 boss
  
• Magicslime 7: 472 monsters, 1 boss
  
• Magicslime 8: 472 monsters, 1 boss
  
• Spider 1: 505 monsters, 0 bosses
  
• Spider 2: 566 monsters, 1 bosses
  
• Spider 3: 690 monsters, 4 bosses
  
• Spider 4: 692 monsters, 6 bosses
  
• Bat 1: 298 monsters, 1 boss
  
• Bat 2: 298 monsters, 1 boss
  
• Bat 3: 395 monsters, 3 bosses
  
• Bat 4: 298 monsters, 4 bosses
  
• Fairy 1: 298 monsters, 1 boss
  
• Fairy 2: 278 monsters, 1 boss
  
• Fairy 3: 395 monsters, 3 bosses
  
• Fairy 4: 395 monsters, 3 bosses
  
• Fox 1: 256 monsters, 1 boss
  
• Fox 2: 316 monsters, 1 boss
  
• Fox 3: 395 monsters, 3 boss
  
• Fox 4: 395 monsters, 3 boss
  
• Devilfish 1: 501 monsters, 1 boss
  
• Devilfish 2: 316 monsters, 1 boss
  
• Devilfish 3: 395 monsters, 3 bosses
  
• Devilfish 4: 395 monsters, 3 bosses
  
• Treant 1: 501 monsters, 1 boss
  
• Treant 2: 316 monsters, 1 boss
  
• Treant 3: 395 monsters, 3 bosses
  
• Treant 4: 395 monsters, 3 bosses
  
• Flametiger 1: 501 monsters, 1 boss
  
• Flametiger 2: 316 monsters, 1 boss
  
• Flametiger 3: 395 monsters, 3 bosses
  
• Flametiger 4: 395 monsters, 3 bosses
  
• Super Dungeons: 2564 monsters, 45 bosses
  
  • No mimics and metals in SDs.
    
  • Bosses are on floors F51 to F99 with the exception of challenge bosses (F60, F70, F80, F90)
    
  • You most likely won't use material multiplier mist even if you have unlocked a utility slot.

[Darnavir]

I'll add it for the sake of being complete, but fox dungeon 2 is not a good source. It scales with difficulty (2 BPs for diff 2, 3 for diff 3...), but doesn't scale with material multiplier mist and is only once per WA. This is bad because most people need a decently sized pile every WA for several ascensions, then passively get enough and have preserved ranks anyways.

The only reliable early game source with high returns is pilfering mimics for now. Fox dungeon 2 can be used for a pearl or 3, but that's nowhere near enough. Some people managed to get quite far with super dungeons alone (portal orbs from title quests, BP drops from boss monsters above F50).

[Artifex]

Fox dungeon 2 rewards a black pearl on first completion per ascension.
This could be a good source for early game seekers who have not unlocked devilish yet.