Well-Laid Plans

The premise of this era was that color combinations mattered, and few enchantments argued the thesis as literally as this one. It rewrites combat math for any two creatures sharing a color: a blue-white flyer and a blue-black blocker simply cannot kill each other in the red zone, because the shared blue zeroes out the damage in both directions. The effect is symmetrical, which gives it its strange shape. It does nothing to a board of disjoint colors, since attackers that share no color with their target still connect normally, so a mono-colored deck swinging into off-color blockers barely notices the enchantment at all. It bites hardest when the table is multicolor, exactly the manabases the period was selling, where most of your board overlaps a color with most of theirs. Note the wording: it prevents damage dealt to creatures by other creatures, not damage to players or planeswalkers, so a deadlocked board still lets attackers chip away at life totals, and creatures simply step around the prevention against any blocker that shares none of their colors. A pinger like Prodigal Sorcerer cannot burn a creature sharing its color, and fight effects fizzle the same way; direct burn from noncreature sources routes around it entirely. So it freezes the ground war among color-overlapping creatures into a staring contest and asks both players to find another axis. That conditional symmetry is also why it stayed a gold-set curiosity: built more to demonstrate color-matters design than to dominate with it.