How Many Pokémon Can You Get with Only Pokémon Alpha Sapphire?
Assuming you do not use any glitches, the answer is 410. The Professor Oak challenge guide for Alpha Sapphire can be found here, although I've made a shorter list of encounters below in case anything happens to the external guide.
The list of Pokémon you cannot get without trading, which equals 311 species, is as follows:
- Two Hoenn Starters (6) - 6 total
- As you can only select one Hoenn starter Pokémon, the other two starters, and their evolutions, are unavailable; this totals 6 Pokémon.
- Two Johto Starters (6) - 12 total
- As you can only select one Johto starter Pokémon, the other two starters, and their evolutions, are unavailable.
- Two Sinnoh Starters (6) - 18 total
- As you can only select one Sinnoh starter Pokémon, the other two starters, and their evolutions, are unavailable.
- Two Unova Starters (6) - 24 total
- As you can only select one Unova starter Pokémon, the other two starters, and their evolutions, are unavailable.
- Trade Evolutions (17) - 41 total
- Golem, Machamp, Alakazam, Kingdra, Huntail, Gorebyss, Rhyperior, Dusknoir, Slowking, Steelix, Electivire, Magmortar, Porygon2, Porygon-Z, Gigalith, Conkeldurr, and Trevenant evolve by trade. Without the ability to trade, they are unobtainable.
- One Fossil Pokémon (2) - 43 total
- As you can only obtain one Fossil on Route 111, you miss out on the other Fossil Pokémon (Lileep or Anorith) and its evolution.
- Version Exclusives (21) - 64 total
- The following Pokémon cannot be obtained without the use of glitches, trading, or events: Seedot, Nuzleaf, Shiftry, Mawile, Zangoose, Solrock, Latios, Groudon, Kabuto, Kabutops, Ho-Oh, Shieldon, Bastiodon, Palkia, Throh, Archen, Archeops, Tornadus, Reshiram, Skrelp, and Dragalge.
- Starter Pokémon (18) - 82 total
- The Kanto and Kalos starter Pokémon must be obtained by trading from X or Y, or transferring from a previous generation.
- Legendary Pokémon (10) - 92 total
- Articuno, Zapdos, Moltres, Mewtwo, Giratina, Landorus, Kyurem, Xerneas, Yveltal, and Zygarde must be obtained by trading from X or Y, or transferring from a previous generation.
- Mythical/Event (15) - 107 total
- Outside of glitches, Mew, Celebi, Jirachi, Phione, Manaphy, Darkrai, Shaymin, Arceus, Victini, Keldeo, Meloetta, Genesect, Diancie, Hoopa, and Volcanion were only obtainable via events that are no longer active, or transferring from previous generations (which requires trading).
- Other (204) - 311 total
- The remaining unobtainable Pokémon are: Caterpie, Metapod, Butterfree, Spearow, Fearow, Ekans, Arbok, Nidoran♀, Nidorina, Nidoqueen, Nidoran♂, Nidorino, Nidoking, Poliwag, Poliwhirl, Poliwrath, Politoed,
Bellsprout, Weepinbell, Victreebel, Farfetch'd, Shellder, Cloyster, Gastly, Haunter, Gengar, Exeggcute, Exeggutor, Cubone, Marowak, Lickitung, Lickilicky, Kangaskhan, Mime Jr., Mr. Mime, Scyther, Scizor,
Smoochum, Jynx, Tauros, Lapras, Munchlax, Snorlax, Dratini, Dragonair, Dragonite, Sentret, Furret, Hoothoot, Noctowl, Ledyba, Ledian, Mareep, Flaaffy, Ampharos, Bonsly, Sudowoodo, Hoppip, Skiploom, Jumpluff,
Yanma, Yanmega, Wooper, Quagsire, Dunsparce, Gligar, Gliscor, Snubbull, Granbull, Qwilfish, Shuckle, Sneasel, Weavile, Teddiursa, Ursaring, Swinub, Piloswine, Mamoswine, Houndour, Houndoom, Smeargle, Miltank,
Larvitar, Pupitar, Tyranitar, Starly, Staravia, Staraptor, Bidoof, Bibarel, Burmy, Wormadam, Mothim, Combee, Vespiquen, Pachirisu, Buizel, Floatzel, Stunky, Skuntank, Riolu, Lucario, Hippopotas, Hippowdon,
Croagunk, Toxicroak, Carnivine, Snover, Abomasnow, Rotom, Patrat, Watchog, Purrloin, Liepard, Pansage, Simisage, Pansear, Simisear, Panpour, Simipour, Woobat, Swoobat, Venipede, Whirlipede, Scolipede,
Basculin, Sigilyph, Solosis, Duosion, Reuniclus, Ducklett, Swanna, Vanillite, Vanillish, Vanilluxe, Emolga, Karrablast, Excavalier, Foongus, Amoonguss, Ferroseed, Ferrothorn, Litwick, Lampent, Chandelure,
Cryogonal, Shelmet, Accelgor, Stunfisk, Mienfoo, Mienshao, Golett, Golurk, Pawniard, Bisharp, Heatmor, Durant, Bunnelby, Diggersby, Fletchling, Fletchinder, Talonflame, Scatterbug, Spewpa, Vivillon,
Litleo, Pyroar, Flabébé, Floette, Florges, Skiddo, Gogoat, Pancham, Pangoro, Furfrou, Espurr, Meowstic, Honedge, Doublade, Aegislash, Spritzee, Aromatisse, Swirlix, Slurpuff, Inkay, Malamar, Helioptile,
Heliolisk, Tyrunt, Tyrantrum, Amaura, Aurorus, Hawlucha, Dedenne, Carbink, Goomy, Sliggoo, Goodra, Pumpkaboo, Gourgeist, Bergmite, Avalugg, Noibat, and Noivern.
Professor Oak Challenge Notes
Pre-Badge 1 (Roxanne) - 40 Total Pokémon
- Gift on Route 101: One starter & its evolutions (3 total)
- Walking on Route 101: Zigzagoon, Linoone (5 total)
- Walking on Route 101: Poochyena, Mightyena (7 total)
- Walking on Route 101: Wurmple, Silcoon, Beautifly, Cascoon, Dustox (12 total) (alternatively, catch Silcoon and Cascoon in Petalburg Woods)
- Walking on Route 103: Wingull, Pelipper (14 total)
- Walking on Route 102: Ralts, Kirlia, Gardevoir (17 total)
- Walking on Route 102: Surskit, Masquerain (19 total)
- Walking on Route 102: Lotad, Lombre (21 total)
- Walking on Route 104: Taillow, Swellow (23 total)
- Walking in Petalburg Woods: Shroomish, Breloom (25 total)
- Walking in Petalburg Woods: Slakoth, Vigoroth, Slaking (28 total)
- In-game Trade in Rustboro City: Makuhita, Hariyama: Trade your Slakoth (30 total)
- Walking on Route 116: Skitty (31 total)
- Walking on Route 116: Whismur, Loudred, Exploud (34 total)
- Walking on Route 116: Nincada, Ninjask, Shedinja (37 total)
- Evolve Skitty with a Moon Stone from Super Training (38 total)
- Evolve male Kirlia with a Dawn Stone from Super Training (39 total)
- Evolve Lombre with a Water Stone from Super Training (40 total)
Badge 1 through Badge 2 (Brawly) - 53 Total Pokémon
Badge 2 through Badge 3 (Wattson) - 80 Total Pokémon
- Gift in Slateport Contest Hall: (Cosplay) Pikachu (54 total)
- Horde on Route 110: Minun (55 total)
- Walking on Route 110: Plusle (56 total)
- Walking on Route 110: Electrike, Manectric (58 total)
- Walking on Route 110: Gulpin, Swalot (60 total)
- Walking on Route 110: Oddish, Gloom (62 total)
- Walking on Route 110: Voltorb, Electrode (64 total)
- Horde on Route 110: Magnemite, Magneton (66 total)
- Evolve Gloom with a Leaf Stone from Super Training (67 total)
- Evolve Gloom with a Sun Stone from Super Training (68 total)
- Walking in Granite Cave B1F and B2F: Aron, Lairon, Aggron (71 total)
- Walking in Granite Cave B2F: Sableye (72 total)
- Walking on Route 117: Volbeat (73 total)
- Walking on Route 117: Illumise (74 total)
- Walking on Route 117: Marill, Azumarill (76 total)
- Walking on Route 117: Roselia (77 total)
- Evolve Roselia with a Shiny Stone from Super Training (78 total)
- Route 117: Breed Roselia or Roserade to get Budew (79 total)
- Route 117: Breed Marill or Azumarill to get Azurill (80 total)
Badge 3 through Badge 4 (Flannery) - 104 Total Pokémon
Badge 3 through Badge 5 (Norman) - 113 Total Pokémon
- Walking on Route 111: Trapinch, Vibrava, Flygon (107 total)
- Walking on Route 111: Cacnea, Cacturne (109 total)
- Walking on Route 111: Baltoy, Claydol (111 total)
- Revive the Root or Claw Fossil in Rustboro City: One of Lileep or Anorith, and its evolution (113 total)
Badges 5 through 6 (Winona) - 133 Total Pokémon
- Walking on Route 115: Jigglypuff, Wigglytuff (115 total)
- Route 117: Breed Jigglypuff or Wigglytuff to get Igglybuff (116 total)
- Level up while walking in New Mauville (both floors): Magnezone (117 total)
- Level up while walking in New Mauville (both floors): Probopass (118 total)
- Fishing (Good Rod) in Petalburg City: Corphish, Crawdaunt (120 total)
- Fishing (Good Rod) in Dewford Town: Wailmer, Wailord (122 total)
- Fishing (Good Rod) on Route 111: Barboach, Whiscash (124 total)
- Fishing (Good Rod) on Route 118: Carvanha, Sharpedo (126 total)
- Gift on Southern Island: Latias (127 total)
- Walking on Route 118: Kecleon (128 total)
- Walking on Route 119: Tropius (129 total)
- Fishing (any Rod) on Route 119: Feebas, Milotic (131 total)
- Gift in the Weather Institute: Castform (132 total)
- Walking on Route 120: Absol (133 total)
Badges 6 through 7 (Tate & Liza) - 170 Total Pokémon
- Walking in Mt. Pyre (all areas): Shuppet, Banette (135 total)
- Walking in Mt. Pyre Inside: Duskull, Dusclops (137 total)
- Walking in Mt. Pyre Outside: Vulpix, Ninetales (139 total)
- Walking in Mt. Pyre Outside: Meditite, Medicham (141 total)
- Walking in Mt. Pyre Summit: Chimecho (142 total)
- Walking in the Safari Zone (all areas): Doduo, Dodrio (144 total)
- Walking in the Safari Zone (all areas): Psyduck, Golduck (146 total)
- Walking in the Safari Zone Area 1 (normal grass): Rhyhorn, Rhydon (148 total)
- Walking in the Safari Zone Area 1 (long grass): Heracross (149 total)
- Walking in the Safari Zone Area 2 (normal grass): Donphan (150 total)
- Walking in the Safari Zone Area 2 (long grass): Pinsir (151 total)
- Walking in the Safari Zone Area 3 (normal grass): Xatu (152 total)
- Walking in the Safari Zone Area 4 (normal grass): Pikachu (evolve into Raichu) (153 total)
- Walking in the Safari Zone Area 4 (long grass): Girafarig (154 total)
- Route 117: Breed Chimecho to get Chingling (155 total)
- Route 117: Breed Donphan to get Phanpy (156 total)
- Route 117: Breed Xatu to get Natu (157 total)
- Route 117: Breed Pikachu or Raichu to get Pichu (158 total)
- Walking in Shoal Cave (all areas): Spheal, Sealeo, Walrein (161 total)
- Walking in Shoal Cave (low tide): Snorunt, Glalie, Froslass (164 total)
- Fishing (Super Rod) in Lilycove City: Staryu, Starmie (166 total)
- Fishing (Super Rod) on Route 128: Luvdisc (167 total)
- Fishing (Super Rod) on Route 128: Corsola (168 total)
- Fishing (Super Rod) on Route 130: Horsea, Seadra (170 total)
Badges 7 through 8 (Wallace) - 387 Total Pokémon
- Underwater on Route 126: Clamperl (171 total)
- Underwater on Route 126: Chinchou, Lanturn (173 total)
- Underwater on Route 126: Relicanth (174 total)
- Static encounter in Desert Ruins: Regirock (175 total)
- Static encounter in Island Cave: Regice (176 total)
- Static encounter in Ancient Tomb: Registeel (177 total)
- Static encounter in the Cave of Origin: Kyogre (178 total)
- Soaring in the sky: Murkrow, Honchkrow (180 total)
- Soaring in the sky: Drifloon, Drifblim (182 total)
- Soaring in the sky: Braviary (183 total)
- Walking on Mirage Island Spots 1, 2, 4, and 8: Venomoth (184 total)
- Walking on Mirage Island Spots 1, 2, 4, and 8 and Mirage Mountain Spot 7: Zebstrika (185 total)
- Walking on Mirage Island Spots 1 and 3 and Mirage Mountain Spot 5: Darmanitan (186 total)
- Walking on Mirage Island Spot 2, Mirage Forest Spots 4, 5, 6, and 7, and Mirage Mountain Spot 3: Tangela, Tangrowth (188 total)
- Walking on Mirage Island Spot 3 and Mirage Forest Spot 3: Larvesta, Volcarona (190 total)
- Walking on Mirage Island Spot 4: Persian (191 total)
- Walking on Mirage Island Spot 5 and Mirage Forest Spots 4, 5, 6, and 7: Purugly (alternatively, catch Glameow in Mirage Forest Spot 7) (192 total)
- Walking on Mirage Island Spot 5 and Mirage Mountain Spot 6: Porygon (193 total)
- Walking on Mirage Island Spot 6, Mirage Forest Spots 2 and 8, and Mirage Mountain Spot 3: Audino (194 total)
- Rock Smash on Mirage Island Spots 6 and 8: Binacle, Barbaracle (196 total)
- Walking on Mirage Island Spot 7 and Mirage Mountain Spot 6: Munna, Musharna (198 total)
- Walking on Mirage Island Spot 7 and Mirage Cave Spot 8: Ditto (199 total)
- Walking on Mirage Island Spot 8: Maractus (200 total)
- Walking in Mirage Forest Spot 1 and Mirage Mountain Spots 1, 2, 4, and 8: Forretress (201 total)
- Walking in Mirage Forest Spot 1 and Mirage Mountain Spot 3: Happiny, Chansey, Blissey (204 total)
- Walking in Mirage Forest Spots 2, 4, 5, 6, 7, and 8: Sunkern, Sunflora (206 total)
- Walking in Mirage Forest Spot 3 and Mirage Mountain Spots 1, 2, 4, and 8: Kricketune (207 total)
- Walking in Mirage Forest Spots 4 and 8: Petilil, Lilligant (209 total)
- Walking in Mirage Forest Spot 5: Cherrim (210 total)
- Walking in Mirage Forest Spot 7: Minccino, Cinccino (212 total)
- Walking in Mirage Cave Spot 1: Unown (213 total)
- Walking in Mirage Cave Spots 2, 3, 4, 6, 7, and 8: Tynamo, Eelektrik, Eelektross (216 total)
- Walking in Mirage Cave Spots 2 and 7: Slowpoke, Slowbro (218 total)
- Walking in Mirage Cave Spots 3, 4, and 5: Klink, Klang, Klinklang (221 total)
- Walking in Mirage Cave Spots 4 and 8: Excadrill (222 total)
- Walking in Mirage Cave Spots 5 and 7: Cofagrigus (223 total)
- Walking in Mirage Mountain Spot 1: Stantler (224 total)
- Walking in Mirage Mountain Spot 4: Vullaby, Mandibuzz (226 total)
- Walking in Mirage Mountain Spot 5: Magby, Magmar (228 total)
- Walking in Mirage Mountain Spot 7: Elekid, Electabuzz (230 total)
- Static encounter on Crescent Isle: Cresselia (231 total)
- Revive an Old Amber (found with Rock Smash in any Mirage Spot) in Rustboro City: Aerodactyl (232 total)
- Revive a Helix Fossil (found with Rock Smash in any Mirage Spot) in Rustboro City: Omanyte, Omastar (234 total)
- Revive a Skull Fossil (found with Rock Smash in any Mirage Spot) in Rustboro City: Cranidos, Rampardos (236 total)
- Revive a Cover Fossil (found with Rock Smash in any Mirage Spot) in Rustboro City: Tirtouga, Carracosta (238 total)
- Static encounter on Pathless Plain: Cobalion (239 total)
- Static encounter on Pathless Plain: Virizion (240 total)
- Static encounter on Pathless Plain: Terrakion (241 total)
- Static encounter in Nameless Cavern: Mesprit (242 total)
- Static encounter in Nameless Cavern: Uxie (243 total)
- Static encounter in Nameless Cavern: Azelf (244 total)
- Static encounter in Fabled Cave: Zekrom (245 total)
- Static encounter in the sky: Dialga (246 total)
- Static encounter in the sky: Thundurus (247 total)
- DexNav on Route 101: Lillipup, Herdier, Stoutland (250 total)
- DexNav on Route 101: Zorua, Zoroark (252 total)
- DexNav on Route 101: Sewaddle, Swadloon, Leavanny (255 total)
- DexNav on Route 103: Chatot (256 total)
- DexNav on Route 103: Shellos, Gastrodon (258 total)
- DexNav on Route 102: Gothita, Gothorita, Gothitelle (261 total)
- DexNav on Route 102: Tympole, Palpitoad, Seismitoad (264 total)
- DexNav on Route 104: Pidove, Tranquill, Unfezant (267 total)
- DexNav in Petalburg Woods: Cottonee, Whimsicott (269 total)
- DexNav in Petalburg Woods: Paras, Parasect (271 total)
- DexNav in Petalburg Woods: Phantump (272 total)
- DexNav on Route 116: Joltik, Galvantula (274 total)
- DexNav on Route 116: Eevee, Vaporeon, Jolteon, Flareon, Espeon, Umbreon, Leafeon, Glaceon, Sylveon (283 total)
- DexNav on Route 105: Frillish, Jellicent (285 total)
- DexNav on Route 105: Krabby, Kingler (287 total)
- DexNav on Route 105: Clauncher, Clawitzer (289 total)
- Static encounter in Island Cave: Regigigas (290 total)
- DexNav in Granite Cave (all floors): Timburr, Gurdurr (292 total)
- DexNav in Granite Cave (all floors): Axew, Fraxure, Haxorus (295 total)
- DexNav in Granite Cave (all floors): Onix (296 total)
- Static encounter in Sea Mauville: Lugia (297 total)
- Static encounter in Sea Mauville: Spiritomb (298 total)
- Static encounter in Trackless Forest: Raikou (299 total)
- Static encounter in Trackless Forest: Entei (300 total)
- Static encounter in Trackless Forest: Suicune (301 total)
- DexNav on Route 110: Trubbish, Garbodor (303 total)
- DexNav on Route 117: Rattata, Raticate (305 total)
- DexNav on Route 117: Deerling, Sawsbuck (307 total)
- DexNav on Route 111: Sandile, Krokorok, Krookodile (310 total)
- DexNav on Route 111: Dwebble, Crustle (312 total)
- DexNav on Route 111: Gible, Gabite, Garchomp (315 total)
- DexNav on Route 112: Ponyta, Rapidash (317 total)
- DexNav on Route 112: Tyrogue, Hitmonlee, Hitmonchan, Hitmontop (321 total)
- DexNav on Route 112: Sawk (322 total)
- DexNav in Fiery Path: Roggenrola, Boldore (324 total)
- DexNav in Fiery Path: Diglett, Dugtrio (326 total)
- DexNav on Route 113: Scraggy, Scrafty (328 total)
- DexNav on Route 113: Klefki (329 total)
- DexNav on Route 113: Bouffalant (330 total)
- DexNav on Route 114: Skorupi, Drapion (332 total)
- DexNav on Route 114: Misdreavus, Mismagius (334 total)
- DexNav in Meteor Falls (all floors): Deino, Zweilous, Hydreigon (337 total)
- DexNav in Meteor Falls (all floors): Druddigon (338 total)
- DexNav in Meteor Falls (all floors): Clefairy, Clefable (340 total)
- DexNav in Jagged Pass: Mankey, Primeape (342 total)
- Gift (Egg) in Lavaridge Town: Togepi, Togetic, Togekiss (345 total)
- DexNav on Route 118: Luxio, Luxray (347 total)
- DexNav on Route 118: Aipom, Ambipom (349 total)
- Static encounter in the Scorched Slab: Heatran (350 total)
- DexNav on Route 121: Elgyem, Beheeyem (352 total)
- DexNav on Route 121: Hypno (353 total)
- DexNav in the Safari Zone (all areas): Kakuna, Beedrill (355 total)
- DexNav in the Safari Zone (all areas): Pidgeotto, Pidgeot (357 total)
- DexNav in the Safari Zone (all areas): Buneary, Lopunny (359 total)
- DexNav on Route 122: Finneon, Lumineon (361 total)
- DexNav on Route 122: Alomomola (362 total)
- DexNav on Mt. Pyre Outside and Summit: Bronzor, Bronzong (364 total)
- DexNav on Mt. Pyre Outside and Summit: Growlithe, Arcanine (366 total)
- DexNav on Route 125: Seel, Dewgong (368 total)
- DexNav on Shoal Cave Entrance, Inner, Stairs, and Lower rooms: Cubchoo, Beartic (370 total)
- DexNav on Shoal Cave Entrance, Inner, Stairs, and Lower rooms: Delibird (371 total)
- Route 117: Breed Braviary to get Rufflet (372 total)
- Route 117: Breed Venomoth to get Venonat (373 total)
- Route 117: Breed Persian to get Meowth (374 total)
- Route 117: Breed Forretress to get Pineco (375 total)
- Route 117: Breed Kricketune to get Kricketot (376 total)
- Route 117: Breed Cherrim to get Cherubi (377 total)
- Route 117: Breed Zebstrika to get Blitzle (378 total)
- Route 117: Breed Excadrill to get Drilbur (379 total)
- Route 117: Breed Darmanitan to get Darumaka (380 total)
- Route 117: Breed Cofagrigus to get Yamask (381 total)
- Route 117: Breed Purugly to get Glameow (382 total)
- Route 117: Breed Clefairy or Clefable to get Cleffa (383 total)
- Route 117: Breed Luxio or Luxray to get Shinx (384 total)
- Route 117: Breed Hypno to get Drowzee (385 total)
- Route 117: Breed Kakuna or Beedrill to get Weedle (386 total)
- Route 117: Breed Pidgeotto or Pidgeot to get Pidgey (387 total)
Badge 8 through Elite Four - 390 Total Pokémon
- Walking in Meteor Falls B1F back: Bagon, Shelgon, Salamence (390 total)
Delta Episode - 177 Total Pokémon
- Gift on Route 101: One Johto starter & its evolutions (393 total)
- Walking in Sky Pillar (all floors): Ariados (394 total)
- Route 117: Breed Ariados to get Spinarak (395 total)
- Static encounter on Sky Pillar: Rayquaza (396 total)
- Static encounter on Sky Pillar: Deoxys (397 total)
Post-Delta Episode - 410 Total Pokémon
- Gift on Route 101: One Unova starter & its evolutions (400 total)
- Gift in Mossdeep City: Beldum, Metang, Metagross (403 total)
- Surfing in the Battle Resort: Mantyke, Mantine (405 total)
- Fishing (Super Rod) in the Battle Resort: Remoraid, Octillery (407 total)
- Gift on Route 101 after beating the Elite Four again: One Sinnoh starter & its evolutions (410 total)