diff --git a/tests/testDispenser.cpp b/tests/testDispenser.cpp
new file mode 100644
index 0000000..5ecc3ff
--- /dev/null
+++ b/tests/testDispenser.cpp
@@ -0,0 +1,128 @@
+#include "testHarness.h"
+#include "vf/Dispenser.h"
+
+using namespace vf;
+
+VF_TEST(dispenserFiresOnlyOnRisingEdge) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::Stone, 5);
+    store.ensure(pos + Vec3i{1, 0, 0}, dispenserSlots);   // container in front
+
+    DispenserState state;
+    CHECK(tickDropper(world, pos, state, store, 0).action == DispenseAction::None);
+    CHECK(tickDropper(world, pos, state, store, 15).action == DispenseAction::InsertedToContainer);
+    CHECK(tickDropper(world, pos, state, store, 15).action == DispenseAction::None);
+    CHECK(tickDropper(world, pos, state, store, 0).action == DispenseAction::None);
+    CHECK(tickDropper(world, pos, state, store, 15).action == DispenseAction::InsertedToContainer);
+
+    CHECK_EQ(store.at(pos + Vec3i{1, 0, 0})->totalItems(), 2);
+    CHECK_EQ(store.at(pos)->totalItems(), 3);
+}
+
+VF_TEST(dispenserPlacesBlockItemIntoAirInFront) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    Vec3i front{6, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::Stone, 1);
+
+    DispenserState state;
+    DispenseResult res = tickDispenser(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::PlacedBlock);
+    CHECK(world.blockAt(front.x, front.y, front.z) == Block::Stone);
+    CHECK_EQ(store.at(pos)->totalItems(), 0);
+}
+
+VF_TEST(dispenserEjectsNonBlockItemIntoFrontContainer) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::IronIngot, 2);
+    store.ensure(pos + Vec3i{1, 0, 0}, dispenserSlots);
+
+    DispenserState state;
+    DispenseResult res = tickDispenser(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::InsertedToContainer);
+    CHECK_EQ(store.at(pos + Vec3i{1, 0, 0})->totalItems(), 1);
+    CHECK_EQ(store.at(pos)->totalItems(), 1);
+}
+
+VF_TEST(dispenserEjectsToWorldWhenItCannotPlaceOrDeposit) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::IronIngot, 1);
+
+    DispenserState state;
+    DispenseResult res = tickDispenser(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::EjectedToWorld);
+    CHECK(static_cast<int>(res.item.item) == static_cast<int>(ItemId::IronIngot));
+    CHECK(world.blockAt(6, 5, 5) == Block::Air);
+}
+
+VF_TEST(dispenserThatCannotPlaceIntoOccupiedCellEjectsInstead) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    world.setBlock(6, 5, 5, Block::Stone);   // front already occupied
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::Dirt, 1);
+
+    DispenserState state;
+    DispenseResult res = tickDispenser(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::EjectedToWorld);
+    CHECK(world.blockAt(6, 5, 5) == Block::Stone);   // unchanged
+}
+
+VF_TEST(dropperNeverPlacesBlocksEvenForBlockItems) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::Stone, 1);
+
+    DispenserState state;
+    DispenseResult res = tickDropper(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::EjectedToWorld);
+    CHECK(world.blockAt(6, 5, 5) == Block::Air);
+}
+
+VF_TEST(dropperDepositsBlockItemIntoFrontContainer) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots).insert(ItemId::Stone, 1);
+    store.ensure(pos + Vec3i{1, 0, 0}, dispenserSlots);
+
+    DispenserState state;
+    DispenseResult res = tickDropper(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::InsertedToContainer);
+    CHECK_EQ(store.at(pos + Vec3i{1, 0, 0})->totalItems(), 1);
+}
+
+VF_TEST(emptyDispenserDoesNothingOnEdge) {
+    World world;
+    Vec3i pos{5, 5, 5};
+    ContainerStore store;
+    store.ensure(pos, dispenserSlots);
+
+    DispenserState state;
+    DispenseResult res = tickDispenser(world, pos, state, store, 15);
+    CHECK(res.action == DispenseAction::None);
+}
+
+VF_TEST(slotSelectionIsDeterministicAndAlwaysHitsAFilledSlot) {
+    Container inventory(9);
+    inventory.setSlot(0, ItemSlot{ItemId::Stone, 10, 0});
+    inventory.setSlot(3, ItemSlot{ItemId::Dirt, 10, 0});
+    inventory.setSlot(7, ItemSlot{ItemId::Sand, 10, 0});
+
+    std::uint32_t rngA = 0x1234abcdu;
+    std::uint32_t rngB = 0x1234abcdu;
+    for (int i = 0; i < 8; ++i) {
+        int a = chooseNonEmptySlot(inventory, rngA);
+        int b = chooseNonEmptySlot(inventory, rngB);
+        CHECK_EQ(a, b);
+        CHECK(!inventory.slot(a).empty());
+    }
+}