Packs are built to match the era each set was printed in. A pack only ever contains cards from its own set.
1993 – Feb 1999 · Alpha through Urza's Saga
| 15 cards | 11 common, 3 uncommon, 1 rare |
| Foils | None — they didn't exist yet |
| Mythics | None — introduced in 2008 |
Feb 1999 – Oct 2008 · Urza's Legacy through Eventide
| 15 cards | 11 common, 3 uncommon, 1 rare |
| Foils | ~1 in 100 cards, replacing a card of the same rarity |
Oct 2008 – Feb 2024 · Shards of Alara through Lost Caverns
| 15 cards | 1 basic land, 10 common, 3 uncommon, 1 rare or mythic |
| Mythic | 1 in 8 |
| Foils | 1 in 67 cards, rising to 1 in 45 from Core Set 2020 |
Feb 2024 onward · Play Boosters
| 14 cards | 6 common, 1 common-or-Special-Guest, 3 uncommon, 1 wildcard, 1 rare or mythic, 1 land, 1 foil wildcard |
| Mythic | 1 in 8 in the rare slot |
Where the numbers come from. The era structures, the 1-in-8 mythic rate and the foil frequencies are published. The per-rarity split of the two Play Booster wildcard slots is not — Wizards only publishes the aggregate of roughly 1.3 rares-or-better per pack. The weights used here reproduce that average, but they're a good-faith model rather than official figures.
Card pools come from each set's real print run via Scryfall, and no card repeats inside a single pack. Prices are Scryfall's current USD market values.