Echo Contingency is a mod-first co-op stealth shooter built for players who miss the precision and tension of classic stealth design. There's no "easy-mode" stealth here. No mark-and-execute, no soft cover snapping, and no go prone to become invisible. Instead, every system is readable, explainable, and punishing but fair. Inspired by the feel, pacing and clarity of early 2000s stealth, Echo Contingency focuses on light, sound, stance, and movement discipline. Detection is never random. Guards react based on real light levels, surface types, and how fast you're moving. If you get spotted, you'll understand exactly why. Metal grating echoes. Carpet absorbs. Water splashes. Every footstep is a