| Mind's Eye (2 variants) | 2704 |
| Mindcrank (2 variants) | 2186 |
| Mindcrank (2 variants) | 2456 |
| Minds Aglow (2 variants) | 7028 |
| Minsc & Boo, Timeless Heroes | 879 |
| Mirage Mirror (2 variants) | 2030 |
| Mirage Mirror | 7025 |
| Miren, the Moaning Well | 7108 |
| Mirkwood Bats (2 variants) | 2565 |
| Mirri, Weatherlight Duelist | 26 |
| Mirror Entity (2 variants) | 2514 |
| Mirror of Galadriel (2 variants) | 1295 |
| Miscast | 2332 |
| Miscast (2 variants) | 2317 |
| Misdirection | 1272 |
| Mishra's Bauble | 2046 |
| Mishra's Bauble (2 variants) | 2041 |
| Mistbind Clique | 116 |
| Mitotic Slime (2 variants) | 2815 |
| Mizzium Mortars (4 variants) | 2249 |
| Mogg Assassin (2 variants) | 2517 |
| Mogg War Marshal (2 variants) | 1618 |
| Moggcatcher | 7081 |
| Mogis, God of Slaughter | 78 |
| Mogis, God of Slaughter (2 variants) | 9994 |
| Moldervine Reclamation (2 variants) | 1716 |
| Molten Collapse (2 variants) | 2677 |
| Moment's Peace | 1466 |
| Moment's Peace | 1466★ |
| Monastery Swiftspear | 2043 |
| Monastery Swiftspear (2 variants) | 2038 |
| Monastery Swiftspear (2 variants) | 216 |
| Monologue Tax | 1838 |
| Monster Manual // Zoological Study (2 variants) | 1782 |
| Moorland Haunt (2 variants) | 349 |
| Morophon, the Boundless | 1896 |
| Morophon, the Boundless | 1944 |
| Mortify (2 variants) | 1801 |
| Mosswort Bridge (2 variants) | 440 |
| Mother of Runes (2 variants) | 298 |
| Mother of Runes (2 variants) | 296 |
| Mother of Runes (2 variants) | 299 |
| Mother of Runes (2 variants) | 473 |
| Mother of Runes (2 variants) | 297 |
| Mountain | 1514 |
| Mountain (2 variants) | 1358 |
| Mountain | 569 |
| Mountain (2 variants) | 106 |
| Mountain | 566 |
| Mountain (2 variants) | 1367 |