diff --git a/tests/testSerialize.cpp b/tests/testSerialize.cpp
new file mode 100644
index 0000000..1aaff71
--- /dev/null
+++ b/tests/testSerialize.cpp
@@ -0,0 +1,73 @@
+#include "testHarness.h"
+#include "vf/Serialize.h"
+#include "vf/Terrain.h"
+
+using namespace vf;
+
+namespace {
+
+bool sameOverRegion(const World& a, const World& b, int xMax, int yMax, int zMax) {
+    for (int x = 0; x < xMax; ++x)
+        for (int y = 0; y < yMax; ++y)
+            for (int z = 0; z < zMax; ++z)
+                if (a.blockAt(x, y, z) != b.blockAt(x, y, z)) return false;
+    return true;
+}
+
+} // namespace
+
+VF_TEST(serializeRoundTripsManualBlocks) {
+    World world;
+    world.setBlock(0, 0, 0, Block::Stone);
+    world.setBlock(1, 2, 3, Block::Grass);
+    world.setBlock(-5, 40, 17, Block::Water);
+    world.setBlock(-5, 41, 17, Block::Leaves);
+
+    std::vector<uint8_t> bytes = serializeWorld(world);
+    World restored;
+    CHECK(deserializeWorld(bytes.data(), bytes.size(), restored));
+
+    CHECK(restored.blockAt(0, 0, 0) == Block::Stone);
+    CHECK(restored.blockAt(1, 2, 3) == Block::Grass);
+    CHECK(restored.blockAt(-5, 40, 17) == Block::Water);
+    CHECK(restored.blockAt(-5, 41, 17) == Block::Leaves);
+    CHECK_EQ(restored.chunkCount(), world.chunkCount());
+}
+
+VF_TEST(serializeRoundTripsTerrain) {
+    TerrainParams params;
+    params.chunksX = 2;
+    params.chunksZ = 2;
+    params.worldHeight = 48;
+    World world;
+    generateTerrain(world, params);
+
+    std::vector<uint8_t> bytes = serializeWorld(world);
+    World restored;
+    CHECK(deserializeWorld(bytes.data(), bytes.size(), restored));
+    CHECK_EQ(restored.chunkCount(), world.chunkCount());
+    CHECK(sameOverRegion(world, restored, 2 * chunkSize, params.worldHeight, 2 * chunkSize));
+}
+
+VF_TEST(serializeRejectsBadMagic) {
+    std::vector<uint8_t> junk = {0x00, 0x11, 0x22, 0x33, 0x44};
+    World out;
+    CHECK(!deserializeWorld(junk.data(), junk.size(), out));
+}
+
+VF_TEST(serializeRejectsTruncatedStream) {
+    World world;
+    world.setBlock(0, 0, 0, Block::Stone);
+    std::vector<uint8_t> bytes = serializeWorld(world);
+    bytes.resize(bytes.size() - 4);   // cut the block stream short
+    World out;
+    CHECK(!deserializeWorld(bytes.data(), bytes.size(), out));
+}
+
+VF_TEST(serializeEmptyWorldRoundTrips) {
+    World world;
+    std::vector<uint8_t> bytes = serializeWorld(world);
+    World restored;
+    CHECK(deserializeWorld(bytes.data(), bytes.size(), restored));
+    CHECK_EQ(restored.chunkCount(), static_cast<std::size_t>(0));
+}