Urza's Legacy Collation

Urza's Legacy is a small set with 55 commons, 44 uncommons, and 44 rares. This is the normal size for a small set of this era. Foil cards are included in booster packs with advertised odds of 1 : 100 cards. This is the first set where foil cards are included in booster packs. The set was printed in the USA and Belgium. [1]

Urza's Legacy was sold in 15 card booster packs. Booster boxes have 36 packs.

US Pack Anatomy

The US printing uses sequential collation with 10 × 11 sheets. Packs are back-facing with commons, then uncommons, and the rare last. If a foil card appears, it will appear in the last slot for a card of the same rarity in the pack. This means, for example, a foil rare will replace the regular rare. (It's not clear if multiple foils can appear in one pack; I haven't seen it.)

11 Commons3 Uncommons1 Rare

There are two common runs, A and B. Run A contains 30 cards each twice, and run B contains 25 cards each twice. The first six commons are from A and the last five are from B. If there is a foil common, it can displace a card from either sequence. (Presumably, a card from A is displaced 6/11 of the time to ensure that A and B cards remain balanced.)

Common Runs

Run A contains 30 cards each twice. Cards are in a repeating color pattern of white, black, green, blue, red. The choice of first card is mostly arbitrary.

UnearthYavimaya WurmWeatherseed FaeriesDefender of ChaosOpal ChampionSick and TiredYavimaya GrangerThornwind FaeriesViashino SandscoutRadiant's Judgment
Giant CockroachSimian GruntsCloud of FaeriesDefender of ChaosEraseSick and TiredYavimaya ScionVigilant DrakeViashino SandscoutDefender of Law
Phyrexian DebaserRancorWeatherseed FaeriesParchExpendable TroopsGiant CockroachYavimaya WurmSlow MotionGoblin MedicsCessation
Plague BeetleSimian GruntsVigilant DrakeViashino BeyErasePhyrexian BroodlingsRancorThornwind FaeriesParchDefender of Law
Plague BeetleYavimaya ScionMiscalculationGoblin MedicsOpal ChampionUnearthTreefolk MysticSlow MotionGhitu SlingerExpendable Troops
Phyrexian DebaserYavimaya GrangerMiscalculationViashino BeyRadiant's JudgmentPhyrexian BroodlingsTreefolk MysticCloud of FaeriesGhitu SlingerCessation

Run B contains 25 cards each twice. Cards are in a repeating color pattern of white, black, green, blue, red. The choice of first card is mostly arbitrary.

SwatCrop RotationBouncing BeeblesPygmy PyrosaurIron WillOstracizeRepopulateInterveneAbout FaceAngelic Curator
Sleeper's GuileWeatherseed ElfBouncing BeeblesLava AxeBurst of EnergyFog of GnatsSilk NetAura FluxGranite GripIron Will
Phyrexian DenouncerMultani's AcolyteSnapAbout FaceDevout HarpistFog of GnatsCrop RotationFrantic SearchPygmy PyrosaurBurst of Energy
SwatWeatherseed ElfSnapGranite GripTragic PoetOstracizeSilk NetInterveneSluggishnessDevout Harpist
Sleeper's GuileMultani's AcolyteAura FluxLava AxeAngelic CuratorPhyrexian DenouncerRepopulateFrantic SearchSluggishnessTragic Poet

[1] The "Compilation of Manufacture Information for MTG Products" thread on the Magic Librarities Forum confirms the existence of Belgian-printed Urza's Legacy, but I couldn't identify any Belgian openings during my research.