SDI
Sega Master System · 1987
About this game
SDI: Strategic Defense Initiative, or simply titled SDI and sometimes known as Global Defense.
Players control a satellite and must destroy enemies by moving a crosshair over them and firing the satellite's weapons.
About Sega Master System
The Sega Master System (1985/1986) was Sega's answer to the NES and, while it lost the console war in North America, became genuinely dominant in markets like Brazil and parts of Europe. That regional split matters for collectors: PAL and Brazilian-market cartridges can differ meaningfully in scarcity and pricing from their North American counterparts for the same title.
Gamevaro tracks SDI for Sega Master System with separate market values for loose, complete-in-box (CIB) and factory-sealed copies, sourced from real eBay sales. Prices also vary by region — PAL, NTSC-U and NTSC-J releases of the same game often sell for different amounts due to print run sizes and regional collector demand.
Adding SDI to a Gamevaro collection takes seconds — search by title or scan the box barcode, and the app fills in cover art, release details and current pricing automatically. This SMS release dates back to 1987.
Market values by condition
NTSC-U
Recent sales
| Date | Type | Region | Price |
|---|---|---|---|
| 2026-07-20 | Loose / Item only | NTSC-U | €61.22 |
Rarity & condition
Only a handful of market sales have been tracked for SDI, suggesting it doesn't trade hands very often — a sign of relative scarcity compared to more common Sega Master System titles.
Complete-in-box (CIB) copies typically command a premium over loose cartridges/discs because the original box and manual are more fragile and get discarded or damaged over time — fewer complete sets survive.
Frequently asked questions
How much is SDI worth?
SDI for Sega Master System is currently worth €61.22 loose. Prices are based on real sales and update regularly on Gamevaro.
Is SDI rare?
SDI has only a handful of tracked market sales, suggesting relative scarcity compared to more common Sega Master System titles.
What's the difference between loose, CIB and sealed for SDI?
Loose means cartridge or disc only, CIB (complete in box) includes the original box and manual, and sealed means factory-sealed and never opened. These are tracked as separate market values because the price gap between them can be significant, especially for older releases.
Ratings & Reviews
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