Design encounters as decisions, not actor counts.

Define objective, available space, enemy roles, spawn timing, hazards, player resources, exits, failure recovery, and reward. Add one pressure source at a time; require each archetype to create a distinct response.

Protect readable paths, telegraphs, camera sight lines, and recovery windows. Cap simultaneous committed attackers and avoid offscreen damage, unavoidable chains, or encounter resets that duplicate rewards.

Create deterministic starts for low resources, each wave, boss phase, victory, and death/retry. Test desktop and mobile at the real camera distance, then adjust composition from observed decisions rather than raw completion time.