Hidden Grottoes
Complete guide to Hidden Grottoes in Pokémon Polished Crystal. Learn about all 22 hidden grotto locations, which Pokémon appear, item drops, and spawn probabilities.
Introduction
Hidden Grottoes are special locations scattered throughout Johto and Kanto where you can find rare Pokémon with their Hidden Abilities and valuable items. Polished Crystal features 22 Hidden Grottoes, each with unique Pokémon encounters that scale dynamically with your badge count.
These grottoes were inspired by the Hidden Grotto feature from Pokémon Black 2 and White 2 (Generation V), but adapted to fit the Pokémon Polished Crystal experience with badge-based level scaling and carefully curated encounter lists.
How Hidden Grottoes Work
Basic Mechanics
- Daily Reset: Hidden Grottoes reset once per day (real-world time)
- Content Types: Each grotto can contain either a Pokémon, a visible item, or a hidden item
- One-Time Use: Once you interact with a grotto (catch the Pokémon or take the item), it becomes empty until the next daily reset
- Badge Scaling: Wild Pokémon levels scale with your badge count using the formula
LEVEL_FROM_BADGES + 0
Spawn Probabilities
When a grotto resets, it randomly determines what appears:
- 50% chance: Pokémon encounter
- 35% chance: Visible item
- 15% chance: Hidden item (requires Itemfinder to detect)
Hidden Abilities
All Pokémon encountered in Hidden Grottoes have their Hidden Ability. This is the primary reason to hunt in grottoes—many powerful Hidden Abilities are otherwise very difficult to obtain.
Level Scaling
Grotto Pokémon levels match your current badge tier exactly:
- 0 badges: Level 4
- 1 badge: Level 8
- 4 badges: Level 20
- 8 badges: Level 36
- 16 badges: Level 61
See Difficulty Scaling Guide for the complete badge level table.
All Grotto Locations
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| mareep | common | 37.5% | Lv. 5 | |
| wooper | common | 37.5% | Lv. 5 | |
| ekans(johto) | uncommon | 20% | Lv. 5 | |
| gastly | rare | 5% | Lv. 5 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| snubbull | common | 37.5% | Lv. 15 | |
| jigglypuff | common | 37.5% | Lv. 15 | |
| yanma | uncommon | 20% | Lv. 15 | |
| ditto | rare | 5% | Lv. 15 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| rattata(alolan) | common | 37.5% | Badge +0 | |
| bellsprout | common | 37.5% | Badge +0 | |
| noctowl | uncommon | 20% | Badge +0 | |
| misdreavus | rare | 5% | Badge +0 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| aipom | common | 37.5% | Badge +3 | |
| weepinbell | common | 37.5% | Badge +3 | |
| raticate | uncommon | 20% | Badge +3 | |
| arbok(johto) | rare | 5% | Badge +3 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| grimer(alolan) | common | 37.5% | Badge +3 | |
| haunter | common | 37.5% | Badge +3 | |
| golbat | uncommon | 20% | Badge +3 | |
| venomoth | rare | 5% | Badge +3 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| farfetchd(galarian) | common | 37.5% | Badge +0 | |
| cubone | common | 37.5% | Badge +0 | |
| machop | uncommon | 20% | Badge +0 | |
| larvitar | rare | 5% | Badge +0 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| graveler | common | 37.5% | Badge +1 | |
| growlithe(hisuian) | common | 37.5% | Badge +1 | |
| skarmory | uncommon | 20% | Badge +1 | |
| dunsparce | rare | 5% | Badge +1 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| swinub | common | 37.5% | Badge +4 | |
| mrmime(galarian) | common | 37.5% | Badge +4 | |
| delibird | uncommon | 20% | Badge +4 | |
| sneasel | rare | 5% | Badge +4 |
| Pokémon | Rarity | Rate | Level | |
|---|---|---|---|---|
| vulpix(alolan) | common | 37.5% | Badge +5 | |
| mrmime(galarian) | common | 37.5% | Badge +5 | |
| growlithe(hisuian) | uncommon | 20% | Badge +5 | |
| sneasel(hisuian) | rare | 5% | Badge +5 |
Pokémon Encounters
Rarity Tiers
Pokémon in each grotto are assigned to rarity tiers:
- Common (60%): Most frequent encounters
- Uncommon (30%): Moderate rarity
- Rare (10%): Hardest to find
Each grotto has 2-4 different Pokémon species with varying rarities.
Notable Hidden Ability Pokémon
Some particularly valuable Hidden Ability Pokémon available in grottoes:
Immunity (Poison immunity):
- Gligar - Found in Mt. Silver grottoes
Multiscale (Reduces damage at full HP):
- Dratini - Dragon's Den grotto
Magic Bounce (Reflects status moves):
- Espeon - Requires breeding from grotto Eevee
Regenerator (Restores 1/3 HP when switching out):
- Slowpoke - Multiple locations
Drizzle (Summons rain):
- Politoed - Evolve grotto Poliwhirl
Item Drops
Visible Items (35% spawn rate)
Common items that can appear in grottoes:
- Evolution Stones (Fire, Water, Thunder, Leaf, Moon, Sun, Dusk, Shiny, Dawn)
- Type-boost items (Charcoal, Mystic Water, Magnet, etc.)
- Berries (Sitrus, Lum, Leppa)
- Evolutionary items (Metal Coat, King's Rock, Upgrade)
Hidden Items (15% spawn rate)
Rarer items that require Itemfinder:
- Rare Candies
- PP Ups
- High-value items (Nugget, Big Mushroom)
- Special evolution items
Rare Items
Each grotto has one special "rare item" that only appears from that specific grotto, making it worth checking regularly.
Hunting Strategies
Daily Grotto Route
Optimize your grotto hunting by planning an efficient route:
- Start in Johto - Check early-game grottoes first
- Use Fly - Minimize travel time between locations
- Bring Itemfinder - Don't miss hidden items (15% of spawns)
- Save before interaction - Soft reset if you want a different nature/IVs
Targeting Specific Pokémon
- Identify your target grotto from the list above
- Visit daily until the desired Pokémon spawns (50% chance for any Pokémon, then rarity within that)
- Save before catching if you want to reset for nature/IVs
- Catch at appropriate level - Higher badges = higher levels = less training needed
Nature Hunting
Hidden Grotto Pokémon have random natures. For competitive Pokémon:
- Save before entering the grotto area
- Check if a Pokémon spawned (50% chance)
- Check the nature in battle
- Soft reset if nature is unfavorable
- Repeat until desired nature appears
Shiny Hunting
Standard shiny rates apply (1/512 in Polished Crystal). Save before interacting with grotto Pokémon and reset if not shiny.
Related Guides
- Difficulty Scaling Guide - Understand how grotto levels scale with badges
- Abilities Guide - Learn about Hidden Abilities and their effects
- Breeding Guide - Pass down Hidden Abilities through breeding
- Shiny Hunting Guide - Maximize your chances of finding shiny grotto Pokémon