diff --git a/app/src/androidTest/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayerTest.kt b/app/src/androidTest/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayerTest.kt
index 182f0bd..7ddc1a8 100644
--- a/app/src/androidTest/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayerTest.kt
+++ b/app/src/androidTest/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayerTest.kt
@@ -1,5 +1,6 @@
 package se.ajpanton.notificationsmaster.alerts
 
+import android.app.NotificationManager
 import androidx.test.platform.app.InstrumentationRegistry
 import org.junit.Assert.assertTrue
 import org.junit.Test
@@ -20,4 +21,20 @@ class AndroidAlertEffectPlayerTest {
         assertTrue(completion.await(2, TimeUnit.SECONDS))
         player.stop()
     }
+
+    @Test
+    fun dndSkipsPlaybackAndCompletesImmediately() {
+        val completion = CountDownLatch(1)
+        val player = AndroidAlertEffectPlayer(
+            InstrumentationRegistry.getInstrumentation().targetContext,
+        ) { NotificationManager.INTERRUPTION_FILTER_NONE }
+
+        player.play(
+            QueuedAlert("test", AlertSnapshot(null, listOf(0, 1_000), false, false)),
+            completion::countDown,
+        )
+
+        assertTrue(completion.await(100, TimeUnit.MILLISECONDS))
+        player.stop()
+    }
 }
diff --git a/app/src/main/java/se/ajpanton/notificationsmaster/AlertRuleDialog.kt b/app/src/main/java/se/ajpanton/notificationsmaster/AlertRuleDialog.kt
index f4c0e11..a8c005f 100644
--- a/app/src/main/java/se/ajpanton/notificationsmaster/AlertRuleDialog.kt
+++ b/app/src/main/java/se/ajpanton/notificationsmaster/AlertRuleDialog.kt
@@ -55,8 +55,15 @@ object AlertRuleDialog {
         val pattern = EditText(context).apply { hint = "Text to match (optional)"; setText(existing?.matcher?.value) }
         val regex = SwitchMaterial(context).apply { text = "Use regular expression"; isChecked = existing?.matcher?.mode == AlertTextMode.REGEX }
         val protected = SwitchMaterial(context).apply { text = "Play to completion"; isChecked = existing?.playToCompletion == true }
-        val dnd = SwitchMaterial(context).apply { text = "Allow during DND when supported"; isChecked = existing?.allowDuringDnd == true }
+        val dnd = SwitchMaterial(context).apply {
+            text = "Allow during DND (requires system support)"
+            isChecked = existing?.allowDuringDnd == true
+        }
         listOf(profile, post, update, pattern, regex, protected, dnd).forEach(form::addView)
+        form.addView(android.widget.TextView(context).apply {
+            text = "Android blocks direct custom alerts during Do Not Disturb. This setting is retained for optional system support, but does not bypass Do Not Disturb in the normal app."
+            textSize = 14f
+        })
         val dialog = MaterialAlertDialogBuilder(context).setTitle(if (existing == null) "Add rule" else "Edit rule")
             .setView(form).setNegativeButton("Cancel", null).setPositiveButton("Save", null)
             .apply { if (onDelete != null) setNeutralButton("Delete", null) }.show()
diff --git a/app/src/main/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayer.kt b/app/src/main/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayer.kt
index baf806c..4a214a3 100644
--- a/app/src/main/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayer.kt
+++ b/app/src/main/java/se/ajpanton/notificationsmaster/alerts/AndroidAlertEffectPlayer.kt
@@ -1,6 +1,7 @@
 package se.ajpanton.notificationsmaster.alerts
 
 import android.content.Context
+import android.app.NotificationManager
 import android.media.AudioAttributes
 import android.media.MediaPlayer
 import android.net.Uri
@@ -12,7 +13,12 @@ import android.os.VibratorManager
 import android.util.Log
 
 /** Plays resolved notification-class effects and releases all platform resources on stop. */
-class AndroidAlertEffectPlayer(context: Context) : AlertEffectPlayer {
+class AndroidAlertEffectPlayer(
+    context: Context,
+    private val interruptionFilter: () -> Int = {
+        context.getSystemService(NotificationManager::class.java).currentInterruptionFilter
+    },
+) : AlertEffectPlayer {
     private val context = context.applicationContext
     private val handler = Handler(Looper.getMainLooper())
     private val vibrator = context.getSystemService(VibratorManager::class.java).defaultVibrator
@@ -27,6 +33,12 @@ class AndroidAlertEffectPlayer(context: Context) : AlertEffectPlayer {
         val token = generation
         completion = onFinished
         val snapshot = alert.snapshot
+        if (!DndPolicy.allowsCustomAlert(interruptionFilter())) {
+            Log.i(TAG, "Skipping custom notification alert during Do Not Disturb")
+            completion = null
+            onFinished()
+            return
+        }
         val vibrationDuration = snapshot.vibrationPattern.sum()
         remainingEffects = (if (snapshot.soundUri == null) 0 else 1) + (if (vibrationDuration > 0) 1 else 0)
         snapshot.soundUri?.let { startSound(Uri.parse(it), token) }
diff --git a/app/src/main/java/se/ajpanton/notificationsmaster/alerts/DndPolicy.kt b/app/src/main/java/se/ajpanton/notificationsmaster/alerts/DndPolicy.kt
new file mode 100644
index 0000000..afc06cf
--- /dev/null
+++ b/app/src/main/java/se/ajpanton/notificationsmaster/alerts/DndPolicy.kt
@@ -0,0 +1,9 @@
+package se.ajpanton.notificationsmaster.alerts
+
+import android.app.NotificationManager
+
+/** Direct custom effects must not bypass the user's Do Not Disturb choice. */
+internal object DndPolicy {
+    fun allowsCustomAlert(interruptionFilter: Int) =
+        interruptionFilter == NotificationManager.INTERRUPTION_FILTER_ALL
+}
diff --git a/app/src/test/java/se/ajpanton/notificationsmaster/alerts/DndPolicyTest.kt b/app/src/test/java/se/ajpanton/notificationsmaster/alerts/DndPolicyTest.kt
new file mode 100644
index 0000000..57bc793
--- /dev/null
+++ b/app/src/test/java/se/ajpanton/notificationsmaster/alerts/DndPolicyTest.kt
@@ -0,0 +1,19 @@
+package se.ajpanton.notificationsmaster.alerts
+
+import android.app.NotificationManager
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class DndPolicyTest {
+    @Test
+    fun allowsCustomAlertsOnlyWhenInterruptionsAreNormal() {
+        assertTrue(DndPolicy.allowsCustomAlert(NotificationManager.INTERRUPTION_FILTER_ALL))
+        listOf(
+            NotificationManager.INTERRUPTION_FILTER_UNKNOWN,
+            NotificationManager.INTERRUPTION_FILTER_PRIORITY,
+            NotificationManager.INTERRUPTION_FILTER_NONE,
+            NotificationManager.INTERRUPTION_FILTER_ALARMS,
+        ).forEach { assertFalse(DndPolicy.allowsCustomAlert(it)) }
+    }
+}