diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/dialogs/CreateDeckDialog.kt b/AnkiDroid/src/main/java/com/ichi2/anki/dialogs/CreateDeckDialog.kt
index fe60d485cf42..8ffe81447dbe 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/dialogs/CreateDeckDialog.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/dialogs/CreateDeckDialog.kt
@@ -194,7 +194,7 @@ class CreateDeckDialog(
             Timber.i("CreateDeckDialog::createNewDeck")
             val newDeckId = getColUnsafe.decks.id(deckName)
             Timber.d("Created deck '%s'; id: %d", deckName, newDeckId)
-            onNewDeckCreated(newDeckId)
+            onNewDeckCreated(newDeckId!!)
         } catch (filteredAncestor: BackendDeckIsFilteredException) {
             Timber.w(filteredAncestor)
             return false
@@ -234,7 +234,7 @@ class CreateDeckDialog(
             try {
                 val decks = getColUnsafe.decks
                 val deckId = decks.id(previousDeckName!!)
-                decks.rename(decks.get(deckId)!!, newName)
+                decks.rename(decks.get(deckId!!)!!, newName)
                 onNewDeckCreated(deckId)
                 // 11668: Display feedback if a deck is renamed
                 displayFeedback(context.getString(R.string.deck_renamed))
diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/provider/CardContentProvider.kt b/AnkiDroid/src/main/java/com/ichi2/anki/provider/CardContentProvider.kt
index a68514c2597d..8f35a3d13314 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/provider/CardContentProvider.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/provider/CardContentProvider.kt
@@ -929,7 +929,7 @@ class CardContentProvider : ContentProvider() {
                     throw IllegalArgumentException("Invalid deck name '$deckName'")
                 }
                 try {
-                    did = col.decks.id(deckName)
+                    did = col.decks.id(deckName)!!
                 } catch (filteredSubdeck: BackendDeckIsFilteredException) {
                     throw IllegalArgumentException(filteredSubdeck.message)
                 }
diff --git a/AnkiDroid/src/main/java/com/ichi2/libanki/Decks.kt b/AnkiDroid/src/main/java/com/ichi2/libanki/Decks.kt
index 57a520fa0b8e..41dac211e5f1 100644
--- a/AnkiDroid/src/main/java/com/ichi2/libanki/Decks.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/libanki/Decks.kt
@@ -34,7 +34,6 @@ import anki.deck_config.UpdateDeckConfigsRequest
 import anki.decks.DeckTreeNode
 import anki.decks.FilteredDeckForUpdate
 import anki.decks.SetDeckCollapsedRequest
-import anki.decks.deck
 import com.google.protobuf.kotlin.toByteStringUtf8
 import com.ichi2.annotations.NeedsTest
 import com.ichi2.libanki.backend.BackendUtils
@@ -52,6 +51,8 @@ import java.util.LinkedList
 typealias UpdateDeckConfigs = UpdateDeckConfigsRequest
 data class DeckNameId(val name: String, val id: DeckId)
 
+const val DEFAULT_DECK_CONF_ID: DeckConfigId = 1L
+
 // TODO: col was a weakref
 
 class Decks(private val col: Collection) {
@@ -98,16 +99,18 @@ class Decks(private val col: Collection) {
     }
 
     /** "Add a deck with NAME. Reuse deck if already exists. Return id as int." */
-    @RustCleanup("add 'create' parameter + change return type")
-    fun id(name: String): DeckId {
-        val id = this.idForName(name)
+    fun id(name: String, create: Boolean = true, type: DeckConfigId = 0L): DeckId? {
+        val id = idForName(name)
         if (id != null) {
             return id
+        } else if (!create) {
+            return null
         }
-        val deck = this.newDeckLegacy(false)
+
+        val deck = this.newDeckLegacy(type != 0L)
         deck.name = name
-        addDeckLegacy(deck)
-        return deck.id
+        val out = addDeckLegacy(deck)
+        return out.id
     }
 
     fun remove(deckIds: Iterable<Long>): OpChangesWithCount {
@@ -157,12 +160,11 @@ class Decks(private val col: Collection) {
         TODO()
     }
 
-    @RustCleanup("implement and make public")
+    /** "Return a new normal deck. It must be added with [addDeck] after a name assigned. */
     @LibAnkiAlias("new_deck")
     @Suppress("unused")
-    /** "Return a new normal deck. It must be added with [addDeck] after a name assigned. */
-    private fun newDeck(): Deck {
-        TODO()
+    fun newDeck(): anki.decks.Deck {
+        return col.backend.newDeck()
     }
 
     @RustCleanup("implement and make public")
@@ -527,7 +529,7 @@ class Decks(private val col: Collection) {
             val deck = if (nameMap != null) {
                 nameMap[parentName]
             } else {
-                get(id(parentName))
+                get(id(parentName)!!)
             }!!
             parents.add(deck)
         }
@@ -561,14 +563,12 @@ class Decks(private val col: Collection) {
      *************************************************************
      */
 
-    /** Return a new dynamic deck and set it as the current deck. */
+    /** For new code, prefer [getOrCreateFilteredDeck] */
     @LibAnkiAlias("new_filtered")
     fun newFiltered(name: String): DeckId {
-        val deck = this.newDeckLegacy(true)
-        deck.name = name
-        addDeckLegacy(deck)
-        this.select(deck.id)
-        return deck.id
+        val did = id(name, type = DEFAULT_DECK_CONF_ID)
+        select(did!!)
+        return did
     }
 
     @LibAnkiAlias("is_filtered")