"The test server is just for developers." Truth: GoodGame actively recruits players. Without player testers, the QA team would never catch edge-case bugs.
: Historically, the server has been used to test crossplay functionality between the PC version and Empire: Four Kingdoms (mobile). Strategic Importance
The Goodgame Empire Public Test Server is a separate environment where Goodgame Studios allows the community to trial upcoming updates before they go live. Its primary goals include:
—that could ruin the experience for the millions of players on the live servers. The Quality Assurance Council
Here’s an interesting, critical-y-enthusiastic review of the GoodGame Empire test server, written for players who are curious about what lies beyond the live game’s walls.