LEGO 3804 Robotics Invention System, Version 2.0

Released 2001 · 720 pieces · Mindstorms · RCX

LEGO Robotics Invention System, Version 2.0 (3804) was released in 2001 in the Mindstorms · RCX line, with 720 pieces. That makes it the 5th largest of the 74 Mindstorms sets in the catalog. It was one of 2 Mindstorms sets released that year. Released in 2001, 25 years ago, well past the two-to-three-year run most LEGO sets get, so it is almost certainly out of production.

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• Estimated value: $163 (modelled from piece count, era, and age, not live market data)

Availability: Likely retired (inferred from its release year, not an official retirement date)

Full details, the price breakdown, and the minifigures included are below. Add it to your collection to track what it's worth.

• The 5th largest of 74 Mindstorms sets
• 23¢ per piece, cheaper per piece than most Mindstorms sets

More from 2001

Set data from the Rebrickable database, refreshed daily. Catalog data as of 2026-09-01. Values are this site's estimates, see how they're calculated.

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