Planar Engineering

The math is the whole trade: two lands sacrificed, four basics onto the battlefield tapped, for a net gain of two lands. That doubling is unusual for green ramp, which historically pays for acceleration in setup time rather than raw count, and the cost side is where the bargain gets paid. You spend a card and four mana to turn generic mana into two additional lands in play, and you shrink your library by four basics on the way, thinning the deck for later draws. The tapped clause pays for the size of the swing: nothing comes online the turn you cast it, so the payoff always lands the following turn and beyond. What separates it from single-land fetch effects is the willingness to eat your own board. It wants surplus lands to sacrifice, whether that means dual-land utility pieces you have finished using or simple basics you would rather stack four-deep in play than draw off the top. Fixing is a side benefit, since you choose the four basics freely and can assemble whatever color spread the rest of your hand demands. This reads as expensive until you count the resource swing across two turns: one card, four mana, and two lands in; four lands and a thinner deck out. It pushes green's setup-time-for-acceleration bargain about as far as it goes without ever letting the mana arrive untapped.