The five areas
Floors 1 to 5 each use a different area with its own enemies, boss pool and arena hazard. From floor 6 the same five areas repeat in darker versions (Shadow Forest, Lunar Grotto, Cursed Tower, Ruined Mansion, Cerulean Abyss), with any floor boss able to appear.
| Floor | Area | Main enemy types | Typical enemies | Boss arena hazard |
|---|---|---|---|---|
| 1 | Viridian Forest | Bug, Poison, Grass, Normal, Flying | Caterpie, Weedle, Rattata, Pidgey, Oddish, Paras | Bushes that slow you and hide shots |
| 2 | Mt. Moon | Rock, Ground (plus Poison, Fairy, Water, Steel) | Zubat, Geodude, Diglett, Clefairy, Kabuto, Larvitar | Stalactites fall when the ground shakes |
| 3 | Pokémon Tower | Ghost, Fairy, Dark | Gastly, Haunter, Drowzee, Cubone, Misdreavus, Litwick | The candles go out |
| 4 | Cinnabar Mansion | Fire, Poison, Electric | Koffing, Grimer, Growlithe, Magmar, Ponyta, Magnemite | Fire grates switch on in turns |
| 5 | Cerulean Cave | Poison, Fighting, Psychic | Golbat, Machoke, Kadabra, Dragonair, Sneasel, Lucario | Psychic runes under your feet |
For each area’s weaknesses at a glance, see the type chart.
All 30 floors
Each row lists the boss pool and when a new item tier starts. How fast the enemies get tougher is covered in the next section.
| Floor | Area | Boss | New item tier |
|---|---|---|---|
| 1 | Viridian Forest | Bug or Grass boss (Beedrill, Scyther, Vileplume…) | Tier 1 |
| 2 | Mt. Moon | Rock or Steel boss (Onix, Steelix, Tyranitar…) | |
| 3 | Pokémon Tower | Ghost or Ground boss (Gengar, Marowak, Chandelure…) | |
| 4 | Cinnabar Mansion | Fire, Poison or Electric boss (Arcanine, Muk, Electivire…) | Tier 2 |
| 5 | Cerulean Cave | Mewtwo | |
| 6–9 | Areas repeat (2nd loop) | Any floor boss | Tier 3 on floor 9 |
| 10 | Cerulean Abyss | Mega boss | |
| 11–14 | 3rd loop | Any floor boss | |
| 15 | Cerulean Abyss | Mewtwo or Mew | Tier 4 |
| 16–19 | 4th loop | Any floor boss | |
| 20 | Cerulean Abyss | Mega boss | |
| 21–24 | 5th loop | Any floor boss | |
| 25 | Cerulean Abyss | Mewtwo or Mew | |
| 26–29 | 6th loop | Any floor boss | |
| 30 | Cerulean Abyss | Armored Mewtwo |
The full boss list with attacks and weaknesses is in the bosses guide.
How the difficulty climbs
The curve changed in v1.0.11. These are the milestones from the game’s own Wiki:
| Floor | Enemy health | Boss health | What else changes |
|---|---|---|---|
| 1–5 | ×1 | ×1 (bosses on floors 1–5 are toned down) | |
| 10 | ×3 | ×2.5 | |
| 11–20 | ×3 → ×14 | Enemies deal +½ heart | |
| 16+ | Ambushes: one combat room in five spawns a second wave, then pays double coins | ||
| 20 | ×14 | ×6 | |
| 21+ | Enemies deal +1 heart; floor bosses gain affixes | ||
| 30 | ×34 | ×12 |
Boss health is also adjusted to your run level (1 to 10), which tracks how strong your build is: from ×0.5 for a weak run up to ×10 for a very strong one. A build that snowballs gets a boss that keeps up.
Item tiers by floor
Better items enter the item pools as you go deeper:
| Tier | Appears from |
|---|---|
| Tier 1 | Floor 1 |
| Tier 2 | Floor 4 |
| Tier 3 | Floor 9 |
| Tier 4 | Floor 15 |
Each point of luck brings these thresholds forward by two floors. Items from Darkrai, Jirachi and secret rooms ignore the floor limit. More in the items guide.
After floor 30: endless mode
Beating Armored Mewtwo ends Classic mode. You can take the win or keep going into endless mode. In the game’s words, even if you fall later, the run still counts as a win.
From floor 31 the run moves through infinite zones of 10 floors each: Frozen Foothills, Sky Pillar, Ashen Crater, Spore Jungle, Observatory, Eternal Graveyard, Distorted Sanctum and The Void. Every 10 floors enemy health goes up ×3.2 and boss health ×2.6, and enemy damage climbs to +2 hearts. Every 10th floor has a shiny Mega boss, with fixed fights against Mega Rayquaza on floor 50, Mega Latias and Mega Latios on floor 80 and Mega Mewtwo Y on floor 100.
How many floors does PokéIsaac have?
Classic mode has 30 floors and ends with Armored Mewtwo on floor 30. After that you can continue into endless mode, which keeps going with a Mega boss every 10 floors.
What is the first floor in PokéIsaac?
Viridian Forest. It is full of Bug, Poison, Grass, Normal and Flying Pokémon, so Fire, Flying and Rock types do well there.
When do stronger items start appearing?
Tier 2 items from floor 4, tier 3 from floor 9 and tier 4 from floor 15. Each point of luck brings these forward by two floors.