Explosion is learned by 39 species by level, 83 by machine, 41 by tutor and 11 by egg

Effect, in PokéAPI's words

“User faints.”

Who learns it

88 species in all, 8 of 24 games shown

Scarlet and Violet: 30 species

Species	Method	Level
Nuzleaf	Level up	1
Seedot	Level up	33
Pineco	Level up	34
Geodude	Level up	36
Forretress	Level up	36
Voltorb	Level up	41
Stunky	Level up	42
Graveler	Level up	44
Golem	Level up	44
Koffing	Level up	44
Drifloon	Level up	44
Electrode	Level up	47
Skuntank	Level up	48
Weezing	Level up	50
Minior	Level up	50
Drifblim	Level up	54
Garganacl	Level up	60
Azelf	Level up	77
Regirock	Level up	78
Regice	Level up	78
Registeel	Level up	78
Regieleki	Level up	78
Regidrago	Level up	78
Volcanion	Level up	90
Magnemite	Egg
Shiftry	Egg
Metagross	Egg
Cryogonal	Egg
Rolycoly	Egg
Glimmet	Egg

Brilliant Diamond and Shining Pearl: 56 species

Species	Method	Level
Nuzleaf	Level up, Machine	1
Shiftry	Level up, Machine	1
Seedot	Level up, Machine	33
Pineco	Level up, Machine	34
Geodude	Level up, Machine	36
Forretress	Level up, Machine	36
Voltorb	Level up, Machine	41
Baltoy	Level up, Machine	42
Graveler	Level up, Machine	44
Golem	Level up, Machine	44
Koffing	Level up, Machine	44
Drifloon	Level up, Machine	44
Stunky	Level up, Machine	45
Electrode	Level up, Machine	47
Claydol	Level up, Machine	48
Weezing	Level up, Machine	50
Lunatone	Level up, Machine	50
Solrock	Level up, Machine	50
Skuntank	Level up, Machine	53
Drifblim	Level up, Machine	54
Azelf	Level up, Machine	77
Regirock	Level up, Machine	78
Regice	Level up, Machine	78
Registeel	Level up, Machine	78
Magnemite	Machine
Magneton	Machine
Grimer	Machine
Muk	Machine
Shellder	Machine
Cloyster	Machine
Gastly	Machine
Haunter	Machine
Gengar	Machine
Onix	Machine
Exeggcute	Machine
Exeggutor	Machine
Mew	Machine
Sudowoodo	Machine
Steelix	Machine
Qwilfish	Machine
Magcargo	Machine
Corsola	Machine
Nosepass	Machine
Gulpin	Machine
Swalot	Machine
Camerupt	Machine
Torkoal	Machine
Glalie	Machine
Metang	Machine
Metagross	Machine
Bronzong	Machine
Bonsly	Machine
Magnezone	Machine
Lickilicky	Machine
Probopass	Machine
Heatran	Machine

Sword and Shield: 32 species

Species	Method	Level
Nuzleaf	Level up	1
Shiftry	Level up	1
Gourgeist	Level up	1
Silvally	Level up	1
Seedot	Level up	33
Baltoy	Level up	42
Trubbish	Level up	42
Koffing	Level up	44
Drifloon	Level up	44
Roggenrola	Level up	44
Stunky	Level up	45
Claydol	Level up	48
Garbodor	Level up	48
Weezing	Level up	50
Lunatone	Level up	50
Solrock	Level up	50
Ferroseed	Level up	50
Turtonator	Level up	52
Skuntank	Level up	53
Drifblim	Level up	54
Boldore	Level up	54
Gigalith	Level up	54
Ferrothorn	Level up	56
Azelf	Level up	77
Regirock	Level up	78
Regice	Level up	78
Registeel	Level up	78
Regieleki	Level up	78
Regidrago	Level up	78
Volcanion	Level up	90
Vanillite	Egg
Rolycoly	Egg

Let's Go Pikachu and Let's Go Eevee: 7 species

Species	Method	Level
Geodude	Level up	35
Voltorb	Level up	45
Graveler	Level up	47
Golem	Level up	47
Koffing	Level up	48
Electrode	Level up	60
Weezing	Level up	60

Ultra Sun and Ultra Moon: 83 species

Species	Method	Level
Regirock	Level up, Machine	1
Regice	Level up, Machine	1
Registeel	Level up, Machine	1
Gourgeist	Level up, Machine	1, 70
Seedot	Level up, Machine	33
Pineco	Level up, Machine	34
Geodude	Level up, Machine	36
Forretress	Level up, Machine	36
Koffing	Level up, Machine	37
Weezing	Level up, Machine	40
Roggenrola	Level up, Machine	40
Voltorb	Level up, Machine	41
Graveler	Level up, Machine	44
Golem	Level up, Machine	44
Lunatone	Level up, Machine	45
Solrock	Level up, Machine	45
Stunky	Level up, Machine	45
Skuntank	Level up, Machine	45
Baltoy	Level up, Machine	46
Electrode	Level up, Machine	47
Trubbish	Level up, Machine	47
Drifloon	Level up, Machine	50
Minior	Level up, Machine	50
Turtonator	Level up, Machine	53
Boldore	Level up, Machine	55
Gigalith	Level up, Machine	55
Ferroseed	Level up, Machine	55
Claydol	Level up, Machine	58
Garbodor	Level up, Machine	59
Drifblim	Level up, Machine	60
Ferrothorn	Level up, Machine	67
Azelf	Level up, Machine	76
Volcanion	Level up, Machine	76
Magnemite	Machine
Magneton	Machine
Grimer	Machine
Muk	Machine
Shellder	Machine
Cloyster	Machine
Gastly	Machine
Haunter	Machine
Gengar	Machine
Onix	Machine
Exeggcute	Machine
Exeggutor	Machine
Mew	Machine
Sudowoodo	Machine
Steelix	Machine
Qwilfish	Machine
Magcargo	Machine
Corsola	Machine
Nuzleaf	Machine
Shiftry	Machine
Nosepass	Machine
Gulpin	Machine
Swalot	Machine
Camerupt	Machine
Torkoal	Machine
Glalie	Machine
Metang	Machine
Metagross	Machine
Bronzong	Machine
Bonsly	Machine
Magnezone	Machine
Lickilicky	Machine
Probopass	Machine
Heatran	Machine
Solosis	Machine
Duosion	Machine
Reuniclus	Machine
Vanillite	Machine
Vanillish	Machine
Vanilluxe	Machine
Cryogonal	Machine
Landorus	Machine
Genesect	Machine
Carbink	Machine
Pumpkaboo	Machine
Diancie	Machine
Silvally	Machine
Celesteela	Machine
Magearna	Machine
Blacephalon	Machine

Sun and Moon: 82 species

Species	Method	Level
Regirock	Level up, Machine	1
Regice	Level up, Machine	1
Registeel	Level up, Machine	1
Gourgeist	Level up, Machine	1, 70
Seedot	Level up, Machine	33
Pineco	Level up, Machine	34
Geodude	Level up, Machine	36
Forretress	Level up, Machine	36
Koffing	Level up, Machine	37
Weezing	Level up, Machine	40
Roggenrola	Level up, Machine	40
Voltorb	Level up, Machine	41
Graveler	Level up, Machine	44
Golem	Level up, Machine	44
Lunatone	Level up, Machine	45
Solrock	Level up, Machine	45
Stunky	Level up, Machine	45
Skuntank	Level up, Machine	45
Baltoy	Level up, Machine	46
Electrode	Level up, Machine	47
Trubbish	Level up, Machine	47
Drifloon	Level up, Machine	50
Minior	Level up, Machine	50
Turtonator	Level up, Machine	53
Boldore	Level up, Machine	55
Gigalith	Level up, Machine	55
Ferroseed	Level up, Machine	55
Claydol	Level up, Machine	58
Garbodor	Level up, Machine	59
Drifblim	Level up, Machine	60
Ferrothorn	Level up, Machine	67
Azelf	Level up, Machine	76
Volcanion	Level up, Machine	76
Magnemite	Machine
Magneton	Machine
Grimer	Machine
Muk	Machine
Shellder	Machine
Cloyster	Machine
Gastly	Machine
Haunter	Machine
Gengar	Machine
Onix	Machine
Exeggcute	Machine
Exeggutor	Machine
Mew	Machine
Sudowoodo	Machine
Steelix	Machine
Qwilfish	Machine
Magcargo	Machine
Corsola	Machine
Nuzleaf	Machine
Shiftry	Machine
Nosepass	Machine
Gulpin	Machine
Swalot	Machine
Camerupt	Machine
Torkoal	Machine
Glalie	Machine
Metang	Machine
Metagross	Machine
Bronzong	Machine
Bonsly	Machine
Magnezone	Machine
Lickilicky	Machine
Probopass	Machine
Heatran	Machine
Solosis	Machine
Duosion	Machine
Reuniclus	Machine
Vanillite	Machine
Vanillish	Machine
Vanilluxe	Machine
Cryogonal	Machine
Landorus	Machine
Genesect	Machine
Carbink	Machine
Pumpkaboo	Machine
Diancie	Machine
Silvally	Machine
Celesteela	Machine
Magearna	Machine

Omega Ruby and Alpha Sapphire: 77 species

Species	Method	Level
Regirock	Level up, Machine	1
Regice	Level up, Machine	1
Registeel	Level up, Machine	1
Gourgeist	Level up, Machine	1, 75
Seedot	Level up, Machine	33
Pineco	Level up, Machine	34
Geodude	Level up, Machine	36
Koffing	Level up, Machine	37
Weezing	Level up, Machine	40
Roggenrola	Level up, Machine	40
Voltorb	Level up, Machine	41
Forretress	Level up, Machine	42
Graveler	Level up, Machine	44
Golem	Level up, Machine	44
Lunatone	Level up, Machine	45
Solrock	Level up, Machine	45
Baltoy	Level up, Machine	46
Electrode	Level up, Machine	47
Trubbish	Level up, Machine	47
Stunky	Level up, Machine	49
Drifloon	Level up, Machine	50
Boldore	Level up, Machine	55
Gigalith	Level up, Machine	55
Ferroseed	Level up, Machine	55
Claydol	Level up, Machine	58
Garbodor	Level up, Machine	59
Drifblim	Level up, Machine	60
Skuntank	Level up, Machine	61
Ferrothorn	Level up, Machine	67
Azelf	Level up, Machine	76
Volcanion	Level up, Machine	76
Magnemite	Machine
Magneton	Machine
Grimer	Machine
Muk	Machine
Shellder	Machine
Cloyster	Machine
Gastly	Machine
Haunter	Machine
Gengar	Machine
Onix	Machine
Exeggcute	Machine
Exeggutor	Machine
Mew	Machine
Sudowoodo	Machine
Steelix	Machine
Qwilfish	Machine
Magcargo	Machine
Corsola	Machine
Nuzleaf	Machine
Shiftry	Machine
Nosepass	Machine
Gulpin	Machine
Swalot	Machine
Camerupt	Machine
Torkoal	Machine
Glalie	Machine
Metang	Machine
Metagross	Machine
Bronzong	Machine
Bonsly	Machine
Magnezone	Machine
Lickilicky	Machine
Probopass	Machine
Heatran	Machine
Solosis	Machine
Duosion	Machine
Reuniclus	Machine
Vanillite	Machine
Vanillish	Machine
Vanilluxe	Machine
Cryogonal	Machine
Landorus	Machine
Genesect	Machine
Carbink	Machine
Pumpkaboo	Machine
Diancie	Machine

X and Y: 77 species

Species	Method	Level
Regirock	Level up, Machine	1
Regice	Level up, Machine	1
Registeel	Level up, Machine	1
Gourgeist	Level up, Machine	1, 75
Pineco	Level up, Machine	34
Koffing	Level up, Machine	37
Weezing	Level up, Machine	40
Roggenrola	Level up, Machine	40
Forretress	Level up, Machine	42
Geodude	Level up, Machine	43
Seedot	Level up, Machine	43
Voltorb	Level up, Machine	47
Trubbish	Level up, Machine	47
Lunatone	Level up, Machine	49
Solrock	Level up, Machine	49
Baltoy	Level up, Machine	49
Stunky	Level up, Machine	49
Drifloon	Level up, Machine	50
Graveler	Level up, Machine	53
Golem	Level up, Machine	53
Boldore	Level up, Machine	55
Gigalith	Level up, Machine	55
Ferroseed	Level up, Machine	55
Electrode	Level up, Machine	57
Garbodor	Level up, Machine	59
Drifblim	Level up, Machine	60
Claydol	Level up, Machine	61
Skuntank	Level up, Machine	61
Ferrothorn	Level up, Machine	67
Azelf	Level up, Machine	76
Volcanion	Level up, Machine	76
Magnemite	Machine
Magneton	Machine
Grimer	Machine
Muk	Machine
Shellder	Machine
Cloyster	Machine
Gastly	Machine
Haunter	Machine
Gengar	Machine
Onix	Machine
Exeggcute	Machine
Exeggutor	Machine
Mew	Machine
Sudowoodo	Machine
Steelix	Machine
Qwilfish	Machine
Magcargo	Machine
Corsola	Machine
Nuzleaf	Machine
Shiftry	Machine
Nosepass	Machine
Gulpin	Machine
Swalot	Machine
Camerupt	Machine
Torkoal	Machine
Glalie	Machine
Metang	Machine
Metagross	Machine
Bronzong	Machine
Bonsly	Machine
Magnezone	Machine
Lickilicky	Machine
Probopass	Machine
Heatran	Machine
Solosis	Machine
Duosion	Machine
Reuniclus	Machine
Vanillite	Machine
Vanillish	Machine
Vanilluxe	Machine
Cryogonal	Machine
Landorus	Machine
Genesect	Machine
Carbink	Machine
Pumpkaboo	Machine
Diancie	Machine

Changed over time

One change since Generation I

1. Through Gen IPower 170250 from Gold and Silver, Generation II