diff --git a/export_presets.cfg b/export_presets.cfg
index 1df6f73..347829e 100644
--- a/export_presets.cfg
+++ b/export_presets.cfg
@@ -9,7 +9,7 @@ custom_features=""
 export_filter="all_resources"
 include_filter=""
 exclude_filter="builds/*,playtest/*,scripts/*"
-export_path="builds/v0.6.6-alpha/windows-x86_64/NETfishing.exe"
+export_path="builds/v0.6.7-alpha/windows-x86_64/NETfishing.exe"
 patches=PackedStringArray()
 encryption_include_filters=""
 encryption_exclude_filters=""
@@ -35,11 +35,11 @@ application/modify_resources=true
 application/icon="res://art/exported/system_icons/netfishing.ico"
 application/console_wrapper_icon=""
 application/icon_interpolation=4
-application/file_version="0.6.6.0"
-application/product_version="0.6.6.0"
+application/file_version="0.6.7.0"
+application/product_version="0.6.7.0"
 application/company_name=""
 application/product_name="NETfishing"
-application/file_description="NETfishing v0.6.6-alpha"
+application/file_description="NETfishing v0.6.7-alpha"
 application/copyright=""
 application/trademarks=""
 application/export_angle=0
@@ -62,7 +62,7 @@ custom_features=""
 export_filter="all_resources"
 include_filter=""
 exclude_filter="builds/*,playtest/*,scripts/*"
-export_path="builds/v0.6.6-alpha/linux-arm64/NETfishing.arm64"
+export_path="builds/v0.6.7-alpha/linux-arm64/NETfishing.arm64"
 patches=PackedStringArray()
 encryption_include_filters=""
 encryption_exclude_filters=""
@@ -92,7 +92,7 @@ custom_features=""
 export_filter="all_resources"
 include_filter=""
 exclude_filter="builds/*,playtest/*,scripts/*"
-export_path="builds/v0.6.6-alpha/macos/NETfishing.zip"
+export_path="builds/v0.6.7-alpha/macos/NETfishing.zip"
 patches=PackedStringArray()
 encryption_include_filters=""
 encryption_exclude_filters=""
@@ -108,8 +108,8 @@ custom_template/release=""
 application/bundle_identifier="io.woofmeow.netfishing"
 application/icon="res://art/exported/system_icons/netfishing_1024.png"
 application/icon_interpolation=0
-application/short_version="0.6.6"
-application/version="0.6.6"
+application/short_version="0.6.7"
+application/version="0.6.7"
 application/architecture="universal"
 codesign/enable=false
 notarization/enable=false
@@ -125,7 +125,7 @@ custom_features=""
 export_filter="all_resources"
 include_filter=""
 exclude_filter="builds/*,playtest/*,scripts/*,tests/*"
-export_path="builds/v0.6.6-alpha/server-linux-x86_64/NETfishingServer.x86_64"
+export_path="builds/v0.6.7-alpha/server-linux-x86_64/NETfishingServer.x86_64"
 patches=PackedStringArray()
 encryption_include_filters=""
 encryption_exclude_filters=""
@@ -155,7 +155,7 @@ custom_features=""
 export_filter="all_resources"
 include_filter=""
 exclude_filter="builds/*,playtest/*,scripts/*"
-export_path="builds/v0.6.6-alpha/android/NETfishing.apk"
+export_path="builds/v0.6.7-alpha/android/NETfishing.apk"
 patches=PackedStringArray()
 encryption_include_filters=""
 encryption_exclude_filters=""
@@ -176,8 +176,8 @@ architectures/armeabi-v7a=false
 architectures/arm64-v8a=true
 architectures/x86=false
 architectures/x86_64=false
-version/code=60600
-version/name="v0.6.6-alpha"
+version/code=60700
+version/name="v0.6.7-alpha"
 package/unique_name="io.woofmeow.netfishing"
 package/name="NETfishing"
 package/signed=true
@@ -214,7 +214,7 @@ custom_features=""
 export_filter="all_resources"
 include_filter=""
 exclude_filter="builds/*,playtest/*,scripts/*"
-export_path="builds/v0.6.6-alpha/linux-x86_64/NETfishing.x86_64"
+export_path="builds/v0.6.7-alpha/linux-x86_64/NETfishing.x86_64"
 patches=PackedStringArray()
 encryption_include_filters=""
 encryption_exclude_filters=""
diff --git a/network/discovery_client.gd b/network/discovery_client.gd
index f2263e8..bdb7134 100644
--- a/network/discovery_client.gd
+++ b/network/discovery_client.gd
@@ -865,12 +865,46 @@ func _parse_response_dictionary(body: PackedByteArray) -> Dictionary:
 func _request_failure(response: Dictionary) -> String:
 	var error: Variant = response.get("error", {})
 	if typeof(error) == TYPE_DICTIONARY:
-		var message: String = str((error as Dictionary).get("message", "")).strip_edges()
+		var details := error as Dictionary
+		if str(details.get("code", "")) == "game_version_mismatch":
+			var required_version: String = str(
+				details.get("required_game_version", "")
+			).strip_edges()
+			if not required_version.is_empty():
+				return _discovery_version_mismatch_message(required_version)
+		var message: String = str(details.get("message", "")).strip_edges()
 		if not message.is_empty():
 			return message
 	return "Room discovery is temporarily unavailable."
 
 
+func _discovery_version_mismatch_message(required_version: String) -> String:
+	var local_version: String = NetworkProtocol.game_version()
+	var rejection: NetworkProtocol.RejectionCode = (
+		NetworkProtocol.game_version_rejection(
+			local_version,
+			required_version,
+		)
+	)
+	match rejection:
+		NetworkProtocol.RejectionCode.CLIENT_OUTDATED:
+			return (
+				"Your NETfishing version is out of date. Update to %s to "
+				+ "enable public discovery. This room will not be listed "
+				+ "until you update."
+			) % required_version
+		NetworkProtocol.RejectionCode.SERVER_OUTDATED:
+			return (
+				"Public discovery is still on NETfishing %s. This room "
+				+ "will not be listed until discovery is updated for %s."
+			) % [required_version, local_version]
+		_:
+			return (
+				"Public discovery requires NETfishing %s. This room will "
+				+ "not be listed until both versions match."
+			) % required_version
+
+
 func _on_session_state_changed(state: NetworkSession.State) -> void:
 	if state == NetworkSession.State.CONNECTING and not _pending_join_token.is_empty():
 		_set_public_join_state(PublicJoinState.CONNECTING)
diff --git a/playtest/README-PLAYTEST.txt b/playtest/README-PLAYTEST.txt
index 042898d..258ea6a 100644
--- a/playtest/README-PLAYTEST.txt
+++ b/playtest/README-PLAYTEST.txt
@@ -1,6 +1,6 @@
 NETfishing
-v0.6.6-alpha
-Alpha 0.6.6
+v0.6.7-alpha
+Alpha 0.6.7
 
 Thank you for trying this early private playtest.
 
diff --git a/project.godot b/project.godot
index 3a76545..27fe914 100644
--- a/project.godot
+++ b/project.godot
@@ -11,7 +11,7 @@ config_version=5
 [application]
 
 config/name="NETFISHING"
-config/version="0.6.6-alpha"
+config/version="0.6.7-alpha"
 run/main_scene="res://main/main.tscn"
 config/features=PackedStringArray("4.7", "GL Compatibility")
 config/icon="res://art/exported/system_icons/netfishing_256.png"
diff --git a/scripts/build_playtest.sh b/scripts/build_playtest.sh
index c0cd14b..3a47661 100755
--- a/scripts/build_playtest.sh
+++ b/scripts/build_playtest.sh
@@ -4,12 +4,12 @@ set -euo pipefail
 
 readonly SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 readonly PROJECT_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
-readonly BUILD_ROOT="${PROJECT_ROOT}/builds/v0.6.6-alpha"
+readonly BUILD_ROOT="${PROJECT_ROOT}/builds/v0.6.7-alpha"
 readonly WINDOWS_DIR="${BUILD_ROOT}/windows-x86_64"
 readonly LINUX_DIR="${BUILD_ROOT}/linux-x86_64"
 readonly README_SOURCE="${PROJECT_ROOT}/playtest/README-PLAYTEST.txt"
-readonly WINDOWS_ZIP="${BUILD_ROOT}/NETfishing-v0.6.6-alpha-windows-x86_64.zip"
-readonly LINUX_ZIP="${BUILD_ROOT}/NETfishing-v0.6.6-alpha-linux-x86_64.zip"
+readonly WINDOWS_ZIP="${BUILD_ROOT}/NETfishing-v0.6.7-alpha-windows-x86_64.zip"
+readonly LINUX_ZIP="${BUILD_ROOT}/NETfishing-v0.6.7-alpha-linux-x86_64.zip"
 readonly GODOT_BIN="${GODOT_BIN:-godot}"
 
 if [[ ! -f "${PROJECT_ROOT}/project.godot" ]]; then
diff --git a/tests/dedicated_server_config_validation.gd b/tests/dedicated_server_config_validation.gd
index 7911f6d..ecc721c 100644
--- a/tests/dedicated_server_config_validation.gd
+++ b/tests/dedicated_server_config_validation.gd
@@ -107,6 +107,46 @@ func _run() -> void:
 			"0.6.5-beta", "0.6.5-alpha"
 		) == NetworkProtocol.RejectionCode.SERVER_OUTDATED
 	)
+	var outdated_discovery_error := {
+		"error": {
+			"code": "game_version_mismatch",
+			"message": "generic mismatch",
+			"required_game_version": "0.6.8-alpha",
+		},
+	}
+	var outdated_message: String = str(
+		discovery.call("_request_failure", outdated_discovery_error)
+	)
+	assert("out of date" in outdated_message)
+	assert("0.6.8-alpha" in outdated_message)
+	assert("will not be listed" in outdated_message)
+	discovery.set(
+		"_host_request_kind",
+		DiscoveryClient.HostRequestKind.CREATE,
+	)
+	discovery.set("_host_request_in_flight", true)
+	discovery.call(
+		"_on_host_request_completed",
+		HTTPRequest.RESULT_SUCCESS,
+		HTTPClient.RESPONSE_CONFLICT,
+		PackedStringArray(),
+		JSON.stringify(outdated_discovery_error).to_utf8_buffer(),
+	)
+	assert(discovery.get_host_state() == DiscoveryClient.HostState.ERROR)
+	assert(discovery.host_status_is_error())
+	assert(discovery.get_host_status_message() == outdated_message)
+	var newer_discovery_error := {
+		"error": {
+			"code": "game_version_mismatch",
+			"message": "generic mismatch",
+			"required_game_version": "0.6.6-alpha",
+		},
+	}
+	var newer_message: String = str(
+		discovery.call("_request_failure", newer_discovery_error)
+	)
+	assert("discovery is updated" in newer_message)
+	assert("will not be listed" in newer_message)
 	discovery.free()
 	print("DEDICATED_SERVER_CONFIG_VALIDATION_OK")
 	quit()
diff --git a/ui/title_screen.tscn b/ui/title_screen.tscn
index d285ea9..285da68 100644
--- a/ui/title_screen.tscn
+++ b/ui/title_screen.tscn
@@ -209,7 +209,7 @@ unique_name_in_owner = true
 layout_mode = 2
 theme_override_colors/font_color = Color(0.682, 0.733, 0.761, 1)
 theme_override_font_sizes/font_size = 22
-text = "v0.6.6-alpha"
+text = "v0.6.7-alpha"
 horizontal_alignment = 1
 
 [node name="Spacer" type="Control" parent="ResponsiveTitleStage/TitlePresentationScaleRoot/Center/MainContent"]