Access Tunnel

A colorless utility land that pays for evasion twice: once in the deck slot it costs to run a land that taps for no colored mana, and again in the three-mana activation you spend to shove something through. The power-3-or-less clause is the whole ceiling. This is not a way to sneak a finisher past a stalled board; it is a way to guarantee that a small, dangerous creature connects, which lines it up with the kind of one- and two-drop that carries a payload rather than raw damage: infect creatures, attackers with hit triggers, or a modestly sized commander-damage clock that only needs to land its swings. The trade the design makes is legibility for flexibility. Rogue's Passage grants unconditional unblockability but demands a heftier activation and no size restriction; this one accepts a strict power cap in exchange for a cheaper repeatable push, and the fixed cost means the evasion is always available regardless of how the game develops, so long as the target stays small enough to qualify. It is a land first and an effect second, which is the point: the ability is upside you access on turns you have mana to spare, not a plan you build the deck around.