Sprite Flicker

Overview

Hardware had limits. Games exceeded them. When the NES could only display 8 sprites per scanline, developers flickered between sprites each frame—showing some objects on even frames, others on odd frames. The result: visible flicker, but more enemies and bullets than the hardware officially supported.

Fast facts

• Purpose: Display more sprites than hardware limit.
• Method: Alternate sprites between frames.
• Trade-off: Visible flickering.
• Necessity: Game design demanded more objects.

NES sprite limits

Limit	Specification
Total sprites	64 maximum
Per scanline	8 maximum
Overflow	Extra sprites invisible
Solution	Flicker rotation

How it works

Frame	Displayed sprites
1	Sprites A, B, C, D
2	Sprites E, F, G, H
3	Sprites A, B, C, D
4	Sprites E, F, G, H

Result: All sprites visible, each at 30fps instead of 60fps.

Implementation approaches

Method	Effect
Priority rotation	Cycle which sprites get priority
Random selection	Vary which sprites shown
Importance weighting	Player sprite never flickers
Scanline distribution	Spread sprites vertically

Games with notable flicker

Game	Situation
Contra	Many enemies/bullets
Mega Man	Boss fights
Gradius	Bullet hell moments
Zelda II	Combat scenes

Alternative solutions

Approach	Trade-off
Fewer objects	Reduced gameplay
Larger sprites	Fewer total
Different design	Avoid crowded scenes
Accept limits	Some sprites disappear

Player perception

Effect	Reception
Mild flicker	Acceptable
Heavy flicker	Distracting
Consistent	Becomes invisible
Erratic	Very noticeable

Platform variations

System	Sprite limit
NES	8 per scanline
Master System	8 per scanline
C64	8 total (hardware)
SNES	32 per scanline

See also

• Sprite Multiplexing
• PPU
• VIC-II