Circle of Protection: Blue

The original Circles are a museum of early Magic's design assumptions: that color identity should be defensible by a single permanent, that a hoser could sit in your opening hand and reshape an entire matchup, and that paying mana repeatedly to blank an opposing source was a fair rate for a one-card answer. The blue Circle is the one whose target color tells the clearest story. In 1993, blue's damage came from a small and predictable set of sources (Mahamoti Djinn, Serendib Efreet, the occasional Psionic Blast), and a single white enchantment that could neutralize all of them, turn after turn, for one mana a pop, was treated as a reasonable sideboard answer rather than a lock. The activation shape is worth reading carefully: it only protects you, and it prevents the next instance of damage from one chosen source, so a board of two blue attackers requires two separate activations. That granularity, and the restriction to damage aimed at your own life total, is what kept the Circles honest as the game's damage sources multiplied. The cycle was a fixture of white sideboards for most of the 1990s and rotated out of the core set after Seventh Edition, retired as Wizards moved away from color-hoser sideboard cards toward more flexible answers. What it preserves is how the earliest designers thought about color balance: with a dedicated, repeatable, single-color valve.