diff --git a/SportsTimeTests/ScenarioAPlannerSwiftTests.swift b/SportsTimeTests/ScenarioAPlannerSwiftTests.swift
index 959aa5b..db17ce7 100644
--- a/SportsTimeTests/ScenarioAPlannerSwiftTests.swift
+++ b/SportsTimeTests/ScenarioAPlannerSwiftTests.swift
@@ -867,4 +867,115 @@ struct ScenarioAPlannerSwiftTests {
         // Game should be excluded (after PST range end)
         #expect(result.failure?.reason == .noGamesInRange)
     }
+
+    // MARK: - Same-Day Multi-City Conflict Tests
+
+    @Test("same-day games in close cities are both included in route")
+    func plan_SameDayGamesCloseCities_BothIncluded() {
+        // LA game at 1pm, San Diego game at 7pm (120 miles, ~2hr drive)
+        let laStadium = makeStadium(city: "Los Angeles", latitude: 34.0522, longitude: -118.2437)
+        let sdStadium = makeStadium(city: "San Diego", latitude: 32.7157, longitude: -117.1611)
+
+        let base = baseDate()
+        let laGame = makeGame(stadiumId: laStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 13))
+        let sdGame = makeGame(stadiumId: sdStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 19))
+
+        let result = plan(
+            games: [laGame, sdGame],
+            stadiums: [laStadium, sdStadium],
+            dateRange: makeDateRange(start: base, days: 10)
+        )
+
+        // Should succeed with both games in route (enough time to drive between)
+        #expect(result.isSuccess)
+        let twoStopOption = result.options.first { $0.stops.count == 2 }
+        #expect(twoStopOption != nil, "Should have route with both cities")
+        #expect(twoStopOption?.totalGames == 2)
+    }
+
+    @Test("same-day games in distant cities only one included per route")
+    func plan_SameDayGamesDistantCities_OnlyOnePerRoute() {
+        // LA game at 1pm, SF game at 7pm (380 miles, ~6hr drive)
+        let laStadium = makeStadium(city: "Los Angeles", latitude: 34.0522, longitude: -118.2437)
+        let sfStadium = makeStadium(city: "San Francisco", latitude: 37.7749, longitude: -122.4194)
+
+        let base = baseDate()
+        let laGame = makeGame(stadiumId: laStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 13))
+        let sfGame = makeGame(stadiumId: sfStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 19))
+
+        let result = plan(
+            games: [laGame, sfGame],
+            stadiums: [laStadium, sfStadium],
+            dateRange: makeDateRange(start: base, days: 10)
+        )
+
+        // Should succeed but each route picks ONE game (cannot attend both same day)
+        #expect(result.isSuccess)
+        for option in result.options {
+            // Each option should have only 1 stop (cannot do both same day)
+            #expect(option.stops.count == 1, "Route should pick only one game - cannot attend both LA and SF same day")
+        }
+    }
+
+    @Test("same-day games on opposite coasts only one included per route")
+    func plan_SameDayGamesOppositCoasts_OnlyOnePerRoute() {
+        // LA game at 1pm PST, NY game at 7pm EST (2800 miles, impossible same day)
+        let laStadium = makeStadium(city: "Los Angeles", latitude: 34.0522, longitude: -118.2437)
+        let nyStadium = makeStadium(city: "New York", latitude: 40.7128, longitude: -74.0060)
+
+        let base = baseDate()
+        let laGame = makeGame(stadiumId: laStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 13))
+        let nyGame = makeGame(stadiumId: nyStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 19))
+
+        let result = plan(
+            games: [laGame, nyGame],
+            stadiums: [laStadium, nyStadium],
+            dateRange: makeDateRange(start: base, days: 10)
+        )
+
+        // Should succeed but each route picks ONE game (obviously impossible same day)
+        #expect(result.isSuccess)
+        for option in result.options {
+            #expect(option.stops.count == 1, "Route should pick only one game - cannot attend both coasts same day")
+        }
+    }
+
+    @Test("three same-day games picks feasible combinations")
+    func plan_ThreeSameDayGames_PicksFeasibleCombinations() {
+        // LA 1pm, Anaheim 4pm (30mi), San Diego 7pm (90mi from Anaheim)
+        // Feasible: LA→Anaheim→SD
+        // Cannot include NY game same day
+        let laStadium = makeStadium(city: "Los Angeles", latitude: 34.0522, longitude: -118.2437)
+        let anaheimStadium = makeStadium(city: "Anaheim", latitude: 33.8003, longitude: -117.8827)
+        let sdStadium = makeStadium(city: "San Diego", latitude: 32.7157, longitude: -117.1611)
+        let nyStadium = makeStadium(city: "New York", latitude: 40.7128, longitude: -74.0060)
+
+        let base = baseDate()
+        let laGame = makeGame(stadiumId: laStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 13))
+        let anaheimGame = makeGame(stadiumId: anaheimStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 16))
+        let sdGame = makeGame(stadiumId: sdStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 19))
+        let nyGame = makeGame(stadiumId: nyStadium.id, dateTime: date(daysFrom: base, days: 0, hour: 19))
+
+        let result = plan(
+            games: [laGame, anaheimGame, sdGame, nyGame],
+            stadiums: [laStadium, anaheimStadium, sdStadium, nyStadium],
+            dateRange: makeDateRange(start: base, days: 10)
+        )
+
+        // Should have options, and best option includes the 3 West Coast games
+        #expect(result.isSuccess)
+
+        // Should have a 3-stop option (LA→Anaheim→SD)
+        let threeStopOption = result.options.first { $0.stops.count == 3 }
+        #expect(threeStopOption != nil, "Should have route with 3 West Coast stops")
+        #expect(threeStopOption?.totalGames == 3)
+
+        // No option should include NY with any other game from same day
+        for option in result.options {
+            let cities = option.stops.map { $0.city }
+            if cities.contains("New York") {
+                #expect(option.stops.count == 1, "NY game cannot be combined with West Coast games same day")
+            }
+        }
+    }
 }