LEGO Set

Robotics Invention System, Version 2.0

3804-1

Released: 2001 · Parts: 720 · Theme: RCX

Robotics Invention System, Version 2.0 (3804-1) is a RCX LEGO set released in 2001 with 720 pieces. Browse the parts list, minifigures, and verify loose bricks with our free scanner. Collectors browsing RCX sets use this inventory to verify loose parts, compare color variants, and read official build manuals without downloading PDFs. This set includes 144 unique part types.

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Buying checklist

Quick context before you buy this set used or verify a marketplace listing.

Release year

2001 (25 years ago — may be retired)
Catalog scale

720 parts listed · 144 inventory lines tracked
Minifigures

No minifigs in inventory (brick-only or Technic set)
Build manual

Digital booklet available on this page — use it to verify bag contents
Build complexity

Large set — expect sticker sheets or multiple subassemblies; inspect photos closely
Gray era

Pre-2004 set — may use old light/dark gray instead of bluish gray
Shipping weight (est.)

~1,452 g for parts inventory (excludes box/minifig packaging)
Before you buy used

Run the completion checker, compare photos to the inventory, and check live listings for sealed pricing

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Market value

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