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Combat DesignJUN 30, 2026 // 9 MIN READ

The math behind frame-perfect parries

A deep dive into hit-stop calculations, input buffering, and making swords feel heavy in Project Ronin.

In action games like Sekiro or Street Fighter, combat satisfaction comes down to millisecond windows. Hit-stop—the intentional freeze of attacker and defender animations for a handful of frames upon weapon contact—creates the illusion of immense kinetic force.

In Project Ronin, we compute hit-stop duration dynamically based on attack velocity, armor resistance, and whether the incoming blow was deflected or blocked. If deflected within our 4-frame window, hit-stop is halved for the player and doubled for the enemy, instantly providing mechanical advantage.

Pairing this with a 6-frame input buffer ensures player inputs feel fluid and responsive even during micro-freezes, completely eliminating input drops.

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