Terastallization — Deep-Dive Reference
Terastallization is the Gen 9 signature mechanic — once per battle, your Pokémon transforms its type into its Tera Type, with cascading effects on damage output, defensive matchup, and STAB calculation. The biggest single mechanical addition since Mega Evolution.
Activation
Once per battle, instant
Tera Types
18 + Stellar (event only)
STAB on match
× 2 if Tera matches original; × 1.5 otherwise
Banned in Gen 9 OU (Tera context)
Ogerpon-W, Terapagos, Last Respects, more
Tera is the only mechanic where every single Pokémon — from Pikachu to Miraidon— gains the same one-time superpower. That equality is what makes it polarizing: it lets bad Pokémon win matches they shouldn't, and good Pokémon win matches they were already winning.
At a glance
Terastallization activates once per battle and changes the Pokémon's typing to its Tera Type for the rest of the match. The change is instant, costs no turn, and cannot be reverted.
- GenerationsGen 9 only — Scarlet/Violet (no equivalent in earlier or later Gen 8 builds)
- Per-battle limitOnce per battle, on one Pokémon, instant activation
- Tera Type assignmentEach Pokémon has a fixed Tera Type, set when caught (random) or chosen via Tera Type Item
- Gen 9 Tera mechanicsRe-typing, STAB recalculation, Tera Blast access, defensive matchup change
- Stellar (post-DLC)Special Tera Type from Indigo Disk DLC — boosts every type once
- Restricted in OUTera-bans on certain Pokémon (Ogerpon-W, Terapagos), some moves with Tera (Last Respects), no full Tera ban as of 2026
How Tera works
When you Terastallize, your Pokémon's active typing — for both offense and defense — becomes the Tera Type. The original typing is replaced (with one Stellar exception covered later).
Mechanically
- Activation: instant, costs no turn. Activates BEFORE the move chosen for that turn.
- Type change: defensive typing replaces both original types. Offensive typing for STAB calculations follows the new Tera Type.
- Move types unchanged: the moves themselves keep their original types. Only the Pokémon's typing changes — meaning the STAB pool may shift (or grow / shrink).
- Persists: lasts for the remainder of the battle. Cannot be undone — even by switching out, the Pokémon stays Terastallized when it returns.
- Tera Type cannot be changed mid-battle — what was assigned at team-building is fixed.
All 18 Tera Types (+ Stellar)
The 18 Tera Types
+ Stellar (DLC)
Tera STAB math
STAB calculation under Tera depends on whether the Tera Type matches the original Pokémon's typing. This is the most subtle and most important rule in Tera.
Two cases
Tera matches original type
STAB on Tera-type moves
× 2.0 (jumps from × 1.5)
STAB on remaining original type
× 1.5 (preserved)
Worked example
Garchomp Tera Dragon — Dragon moves × 2 STAB. Ground moves still × 1.5.
Tera differs from original type
STAB on Tera-type moves
× 1.5 (standard)
STAB on original types
Lost — × 1.5 → × 1.0
Worked example
Garchomp Tera Steel — Steel moves × 1.5 STAB. Ground/Dragon moves drop from × 1.5 back to × 1.0.
The math
The 2.0× edge case worked example
Roaring Moon Tera Dark + Knock Off:
- Original types: Dragon / Dark.
- Tera Dark = matches one original type (Dark).
- Knock Off (Dark-type) is now × 2 STAB instead of × 1.5.
- Combined with 145 BP from Dark Pulse / Knock Off proc, this is among the heaviest single hits in OU.
Tera Blast — the universal Tera move
Tera Blast is a TM move that adapts to the user's Tera Type. Without Terastallizing, it's a 80 BP Normal-type special move. After Terastallization, it becomes the Tera Type and uses whichever of Attack or Sp.Atk is higher.
Tera Blast mechanics
- Base: 80 BP, special, Normal-type, 100% accuracy, 10 PP.
- Pre-Tera: behaves like a 80 BP Normal-type Tackle.
- Post-Tera: type changes to match Tera Type, becomes physical OR special (whichever stat is higher).
- STAB: applies normally based on the Tera Type rules above.
- No additional effect: no secondary, no priority. Pure damage move.
Why Tera Blast matters
- Universal coverage: any Pokémon can hit any type by setting the right Tera Type + Tera Blast. Solves coverage gaps that standard movepools couldn't.
- Mixed-attacker ratio: a physically-biased Pokémon can use Tera Blast as a special hit (or vice versa) by choosing the right stat distribution.
- Surprise factor: opponents can't see Tera Type from team preview alone; Tera Blast is the catch-all that exploits this hidden info.
- Stellar variant: Tera Blast Stellar is a special move that hits Pokémon-Tera Stellar super-effectively (only relevant in matches with Terapagos in the field).
Stellar Tera Type
Stellar is a special Tera Type added in The Indigo Disk DLC (December 2023). It's the only Tera Type not based on a regular type, and it has unique mechanical interactions.
Stellar Tera mechanics
- Damage boost: each move type used by a Stellar-Tera Pokémon receives a one-shot × 2 STAB boost the FIRST time it's used (× 2.25 if move was already STAB pre-Tera). Subsequent uses of the same type drop to × 1.2 for the rest of the battle.
- Original typing preserved: unlike normal Tera, Stellar Tera does NOT change the Pokémon's defensive typing. It stays at its original two types defensively.
- Tera Blast Stellar: special variant — hits Stellar-Tera Pokémon super-effectively, bypassing the Stellar "invulnerability" angle.
- Availability: limited to Mythical Pokémon (Mew, Terapagos) and event Pokémon only. Cannot be assigned to standard Pokémon via Tera Type item.
The Stellar boost — worked example
Mew with Tera Stellar using Psychic, then Aura Sphere, then Psychic again:
- Turn 1: Psychic — × 2 boost (first Psychic), since Psychic was original STAB → × 2.25 effective.
- Turn 2: Aura Sphere — × 2 boost (first Fighting), Mew has no Fighting STAB → × 2.0 effective.
- Turn 3: Psychic again — × 1.2 boost (already-used Psychic).
Defensive vs offensive Tera
Every Tera assignment is a tradeoff between offensive boost (more damage, surprise coverage) and defensive shift (remove weaknesses, gain resistances). The two strategies are roughly opposite.
Defensive Tera
Goal
Remove weaknesses or gain immunities to survive a key opposing move.
Examples
Tera Fairy on Garchomp (immune to Dragon, no longer Ice 4×), Tera Steel on Iron Hands (resists most things), Tera Ghost on Garchomp/Tyranitar (immune to Earthquake/Fighting).
Tradeoff
Loses STAB on original types (× 1.5 → × 1.0), no offensive boost.
Best for
Bulky Pokémon, defensive cores, Tera-on-reaction usage.
Offensive Tera
Goal
× 2 STAB on a key move to break a wall, or new STAB on a coverage move.
Examples
Tera Flying on Kingambit (× 2 STAB Aerial Ace), Tera Dragon on Roaring Moon (× 2 Dragon Claw), Tera Fighting on Iron Valiant (× 2 Close Combat).
Tradeoff
Defensive typing changes — may gain new weaknesses.
Best for
Setup sweepers, breaker rolls, kill plays.
Pokémon redefined by Tera
Tera is so impactful that it has fundamentally redefined how certain Pokémon function in Gen 9. The list below covers Pokémon whose viability is centered on a specific Tera Type.
Pokémon whose value depends on Tera
| Pokémon | Common Tera | Why it matters |
|---|---|---|
| Kingambit | Flying | Tera Flying gives × 2 STAB on Air Slash for OHKO on bulky Heatrans, plus immunity to Earthquake. The defining offensive Tera in OU 2024-25. |
| Iron Valiant | Fairy / Fighting | Tera Fighting × 2 Close Combat 1HKOs Toxapex, Skeledirge, Heatran. Tera Fairy nukes Roaring Moon. |
| Roaring Moon | Dark / Dragon | Both options give × 2 STAB on its main moves. Tera Dragon hits Walking Wake. Tera Dark makes Knock Off / Crunch into nukes. |
| Ogerpon-Wellspring | Water (forced) | Banned. Locked Tera Water + Water Absorb on Tera made it a free defensive pivot. Single biggest Tera-related ban. |
| Terapagos | Stellar (forced) | Banned. Tera Blast Stellar plus the auto-Stellar form change made it Anything Goes-tier. |
| Gholdengo | Fighting / Flying | Tera Fighting on Make It Rain set hits Rotom-Wash. Tera Flying for Earthquake immunity. |
| Dragapult | Ghost / Fairy | Tera Ghost gives × 2 Shadow Ball for breakthrough. Tera Fairy avoids Dragon revenge. |
| Hatterene | Fire / Water | Tera Fire bypasses Steel resists. Tera Water tanks Steel coverage. |
Banlist & competitive impact
Smogon's tiering committees deliberated for over a year on whether to ban Tera entirely. The eventual compromise: keep Tera, ban specific Pokémon and specific moves whose Tera interaction was ungovernable.
Tera-driven bans in Gen 9 OU (as of April 2026)
| Banned entity | Why | Status |
|---|---|---|
| Ogerpon-Wellspring | Forced Tera Water + Water Absorb on Tera = free defensive pivot. Could not be matched in counterplay. | Banned (suspect → quickban path) |
| Terapagos | Tera Blast Stellar plus signature ability + form change. Powercrept the format. | Banned (Anything Goes only) |
| Last Respects | Power scales with fallen teammates. With Tera Ghost (Houndstone), uncounterable late-game cleaner. | Banned (move-level) |
| Shed Tail | Sets up free Tera-pivot in opponent's face. Mostly a Cyclizar issue. | Banned (move-level + Cyclizar tier-banned) |
| Various other Pokémon | Annihilape, Ursaluna-Bloodmoon, Volcarona — Tera enabled too much. | Banned (varies by suspect) |
Tera Preview rule
Smogon Tera Preview: from late 2024 onward, Smogon Singles formats added Tera Preview— opponent sees each Pokémon's Tera Type at team preview. This shifted Tera from a hidden mechanic to a partial-info mechanic and reduced (but did not eliminate) the surprise/RNG dimension.
Official VGC: Tera Preview applies in VGC from Reg G (2024) onward. Opens up counter-Tera-typing as a teambuilding axis.
Tera by format
Tera works the same mechanically across Singles and Doubles, but the strategy differs significantly.
Smogon OU (Singles)
Commit ratio
1-of-6 — you pick the right time across 6 turns.
Common usage
Defensive Tera dominates — flip to survive a kill.
Offensive Tera
Reserved for sweepers (DD users, Choice Specs).
Tera Preview
On — opponent sees Tera Type from team preview.
VGC (Doubles)
Commit ratio
1-of-4 (or 1-of-6 from Reg G) — earlier Tera flips are common.
Common usage
Offensive Tera dominates — format runs hotter, Tera is for breaker plays.
Spread interaction
Tera + spread move drives usage (Tera Fighting + Sacred Sword, Tera Steel + Make It Rain).
Tera Preview
Standard from Reg G onward.
Tera in Pokémon Champions (Reg M-A 2026)
Pokémon Champions (April 2026 launch) inherits Tera mechanics from Gen 9 since Reg M-A is built on Scarlet/Violet's engine. Tera Preview is on by default. This is the first format outside SV to feature Tera, and the format is still finding its identity. See the Pokémon Champions Era guide.
Common misconceptions
- "Tera Type changes the moves' types" — wrong. The moves keep their original types. Only the Pokémon's typing for STAB and resistance/weakness purposes changes.
- "Tera × 2 always" — false. The × 2 STAB only applies if the Tera Type matches the Pokémon's ORIGINAL type. Tera Flying on Kingambit (originally Dark/Steel) does NOT × 2 because Flying isn't Dark or Steel — it's × 1.5 STAB on Tera Blast.
- "Tera removes the original types entirely" — for normal Tera, yes (defensive typing replaces). For Stellar Tera, NO — original types stay defensively.
- "You can re-Tera mid-battle" — wrong. Once Terastallized, the form persists for the rest of the match. No Pokémon, no item, no ability undoes it.
- "Tera resets on switch" — wrong. Switch out, switch back in: the Pokémon is still Terastallized.
- "Stellar boosts every move forever" — wrong. Stellar gives × 2 STAB ONCE per type per battle. Subsequent uses are × 1.2.
- "Tera is fully banned in OU" — false. Specific Pokémon (Ogerpon-W, Terapagos) and specific move/item combinations are banned. The base Tera mechanic remains legal.
Where to go from here
Tera's impact extends across teambuilding, damage calculation, and match scouting. The pages below cover those layers.
- Damage formula — Damage Formula covers exactly how the × 2 / × 1.5 STAB interacts with type effectiveness.
- Type chart — Type Chart covers all 18-type matchups Tera can shift you into or out of.
- Gen 9 Era — Gen 9 Scarlet/Violet for full historical context: how Tera shaped the meta from launch to 2026.
- Gen 9 OU — Gen 9 OU format guide covers the format-specific banlist and current archetypes.
- Pokémon Champions — Pokémon Champions Era for the new Reg M-A meta with Tera.
- Live data — Gen 9 OU usage shows current Tera Type breakdown per Pokémon.