Plateau

Both basic land types printed on a single card, no entry tax, no untapped condition, no life paid, not a word of restriction anywhere: this is the original two-color manabase, one of the ten Alpha duals against which every fixing land since has been priced. The design is brutally efficient, and the load-bearing detail is the type line. Because the card is a Mountain and a Plains, every fetchland that searches for either basic type finds it, every effect keyed to those land types reads it, and every land-search or land-destruction interaction treats it as both. The cycle established the principle that color fixing at zero cost is a power ceiling later designers keep retreating from: shocklands tax your life total, checklands gate on a prior untapped land, painlands bleed you for the privilege, surveil lands surrender a turn by entering tapped. Each restriction exists because the original duals proved how much a manabase warps when fixing is genuinely free. The Reserved List has frozen this card in its Alpha-through-Revised printings, which is why it now functions less as a playable object and more as a benchmark: the platonic red-white land that every red-white land since has been a deliberate compromise against.