Is Rillaboom viable in Gen 9 VGC 2026 Reg I (Bo3)?

Rillaboom is ranked #5 in Gen 9 VGC 2026 Reg I (Bo3) with 29.32% usage according to Smogon Feb 2026 - Apr 2026 data.

What beats Rillaboom in Gen 9 VGC 2026 Reg I (Bo3)?

The best counter for Rillaboom in Gen 9 VGC 2026 Reg I (Bo3) is Calyrex-Ice with a 47.7% win rate when they meet. Based on Smogon's Feb 2026 - Apr 2026 usage data, the top Pokémon that beat Rillaboom include Calyrex-Ice, Kyogre, Urshifu-Rapid-Strike, Miraidon, Incineroar.

What is the best counter for Rillaboom in Gen 9 VGC 2026 Reg I (Bo3)?

Calyrex-Ice is the best counter for Rillaboom in Gen 9 VGC 2026 Reg I (Bo3), KOing or forcing it out in 47.7% of their encounters.

Rillaboom counters

Gen 9 VGC 2026 Reg I (Bo3) · Sorted by reliability score · Smogon · Feb 2026 - Apr 2026

#0812 Rillaboom

Grass

USAGE 29.3% #5

ABILITYGrassy Surge

BASE STATS

HP 100

ATK 125

DEF 90

SPA 60

SPD 70

SPE 85

BST530

TYPE MATCHUPS

2×

FireIcePoisonFlyingBug

½×

WaterElectricGrassGround

Moves

Fake Out 100.0% Grassy Glide 99.9% U-turn 97.9% Wood Hammer 92.3% Drum Beating 7.4% Taunt 1.1% High Horsepower 0.6% Knock Off 0.6%

Items

Assault Vest 95.5% Meadow Plate 2.4% Focus Sash 1.4% Miracle Seed 0.6% Grassy Seed 0.1% Sitrus Berry 0.0% Choice Band 0.0% Clear Amulet 0.0%

Abilities

Grassy Surge100.0%Overgrow0.0%

Tera Types

Water 60.9% Fire 35.1% Grass 3.3% Poison 0.3% Normal 0.2% Bug 0.1% Fairy 0.0% Ghost 0.0%

Common Teammates

Zamazenta-Crowned25.9%

Smeargle25.5%

Urshifu-Rapid-Strike22.7%

Checks & Counters

Ranked by reliability — blends KO rate with how often each Pokémon is matched up.

# Checker Encounters Reliability KO Rate

Calyrex-Ice

PsychicIce SOFT CHECK

21.366

47.7% dies 10.81%

DAMAGE CALCGrassy Terrain

252+ Atk Calyrex-Ice Glacial Lance vs. 252 HP / 0 Def Rillaboom: 294-348 (142 - 168.1%) -- guaranteed OHKO

View Calyrex-Ice counters → Teams with Calyrex-Ice →

Kyogre

Water SOFT CHECK

21.955

42.2% dies 10.54%

DAMAGE CALCRain

252+ SpA Mystic Water Kyogre Water Spout (150 BP) vs. 252 HP / 252+ SpD Assault Vest Rillaboom in Rain: 84-99 (40.5 - 47.8%) -- guaranteed 3HKO

View Kyogre counters → Teams with Kyogre →

Urshifu-Rapid-Strike

FightingWater SOFT CHECK

22.9

41.7% dies 10.30%

DAMAGE CALCGrassy Terrain

252+ Atk Choice Band Urshifu-Rapid-Strike Close Combat vs. 252 HP / 0 Def Rillaboom: 186-219 (89.8 - 105.7%) -- 37.5% chance to OHKO

View Urshifu-Rapid-Strike counters → Teams with Urshifu-Rapid-Strike →

Miraidon

ElectricDragon SOFT CHECK

63.114

38.5% dies 6.13%

DAMAGE CALCElectric Terrain

252+ SpA Hadron Engine Miraidon Draco Meteor vs. 252 HP / 252+ SpD Assault Vest Rillaboom: 100-118 (48.3 - 57%) -- 89.1% chance to 2HKO

View Miraidon counters → Teams with Miraidon →

Incineroar

FireDark SOFT CHECK

52.288

36.6% dies 6.66%

DAMAGE CALCGrassy Terrain

252+ Atk Incineroar Flare Blitz vs. 252 HP / 0 Def Rillaboom: 224-266 (108.2 - 128.5%) -- guaranteed OHKO

View Incineroar counters → Teams with Incineroar →

Ranked #5 with 29.32% usage. Sorted by reliability score.