secondary-action-mastery

Secondary action adds life to a scene without distracting from the main action. A character walking (primary) while whistling and swinging their arms (secondary). A button pressing (primary) with a subtle ripple effect (secondary). It's the difference between functional animation and rich, immersive motion.

Subordination principle: Secondary action must never compete with primary action. If viewers watch the secondary instead of primary, you've failed. The supporting role must remain supporting.

Reinforcement function: Good secondary action reinforces the primary action's meaning. It doesn't just add motion—it adds dimension to the story being told.

Use when enriching primary animations, adding supporting details, creating depth in motion, or making scenes feel alive without distracting from main action. Source: dylantarre/animation-principles.