diff --git a/vector/src/androidTest/java/im/vector/app/features/roomdirectory/ExplicitTermFilterTest.kt b/vector/src/androidTest/java/im/vector/app/features/roomdirectory/ExplicitTermFilterTest.kt
new file mode 100644
index 0000000000..b2beec5b66
--- /dev/null
+++ b/vector/src/androidTest/java/im/vector/app/features/roomdirectory/ExplicitTermFilterTest.kt
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2021 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package im.vector.app.features.roomdirectory
+
+import im.vector.app.InstrumentedTest
+import im.vector.app.core.utils.AssetReader
+import org.amshove.kluent.shouldBe
+import org.junit.FixMethodOrder
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import org.junit.runners.MethodSorters
+
+@RunWith(JUnit4::class)
+@FixMethodOrder(MethodSorters.JVM)
+class ExplicitTermFilterTest : InstrumentedTest {
+
+    private val explicitTermFilter = ExplicitTermFilter(AssetReader(context()))
+
+    @Test
+    fun isValidEmptyTrue() {
+        explicitTermFilter.isValid("") shouldBe true
+    }
+
+    @Test
+    fun isValidTrue() {
+        explicitTermFilter.isValid("Hello") shouldBe true
+    }
+
+    @Test
+    fun isValidFalse() {
+        explicitTermFilter.isValid("nsfw") shouldBe false
+    }
+
+    @Test
+    fun isValidUpCaseFalse() {
+        explicitTermFilter.isValid("Nsfw") shouldBe false
+    }
+
+    @Test
+    fun isValidMultilineTrue() {
+        explicitTermFilter.isValid("Hello\nWorld") shouldBe true
+    }
+
+    @Test
+    fun isValidMultilineFalse() {
+        explicitTermFilter.isValid("Hello\nnsfw") shouldBe false
+    }
+
+    @Test
+    fun isValidMultilineFalse2() {
+        explicitTermFilter.isValid("nsfw\nHello") shouldBe false
+    }
+
+    @Test
+    fun isValidAnalFalse() {
+        explicitTermFilter.isValid("anal") shouldBe false
+    }
+
+    @Test
+    fun isValidAnal2False() {
+        explicitTermFilter.isValid("There is some anal in this room") shouldBe false
+    }
+
+    @Test
+    fun isValidAnalysisTrue() {
+        explicitTermFilter.isValid("analysis") shouldBe true
+    }
+
+    @Test
+    fun isValidAnalysis2True() {
+        explicitTermFilter.isValid("There is some analysis in the room") shouldBe true
+    }
+
+    @Test
+    fun isValidSpecialCharFalse() {
+        explicitTermFilter.isValid("18+") shouldBe false
+    }
+
+    @Test
+    fun isValidSpecialChar2False() {
+        explicitTermFilter.isValid("This is a room with 18+ content") shouldBe false
+    }
+
+    @Test
+    fun isValidOtherSpecialCharFalse() {
+        explicitTermFilter.isValid("strap-on") shouldBe false
+    }
+
+    @Test
+    fun isValidOtherSpecialChar2False() {
+        explicitTermFilter.isValid("This is a room with strap-on content") shouldBe false
+    }
+
+    @Test
+    fun isValid18True() {
+        explicitTermFilter.isValid("18") shouldBe true
+    }
+
+    @Test
+    fun isValidLastFalse() {
+        explicitTermFilter.isValid("zoo") shouldBe false
+    }
+
+    @Test
+    fun canSearchForFalse() {
+        explicitTermFilter.canSearchFor("zoo") shouldBe false
+    }
+
+    @Test
+    fun canSearchForTrue() {
+        explicitTermFilter.canSearchFor("android") shouldBe true
+    }
+}
diff --git a/vector/src/main/assets/forbidden_terms.txt b/vector/src/main/assets/forbidden_terms.txt
new file mode 100644
index 0000000000..84e7fe1d28
--- /dev/null
+++ b/vector/src/main/assets/forbidden_terms.txt
@@ -0,0 +1,68 @@
+anal
+bbw
+bdsm
+beast
+bestiality
+blowjob
+bondage
+boobs
+clit
+cock
+cuck
+cum
+cunt
+daddy
+dick
+dildo
+erotic
+exhibitionism
+faggot
+femboy
+fisting
+flogging
+fmf
+foursome
+futa
+gangbang
+gore
+h3ntai
+handjob
+hentai
+incest
+jizz
+kink
+loli
+m4f
+masturbate
+masturbation
+mfm
+milf
+moresome
+naked
+neet
+nsfw
+nude
+nudity
+orgy
+pedo
+pegging
+penis
+petplay
+porn
+pussy
+rape
+rimming
+sadism
+sadomasochism
+sexy
+shota
+spank
+squirt
+strap-on
+threesome
+vagina
+vibrator
+voyeur
+watersports
+xxx
+zoo
diff --git a/vector/src/main/java/im/vector/app/features/roomdirectory/ExplicitTermFilter.kt b/vector/src/main/java/im/vector/app/features/roomdirectory/ExplicitTermFilter.kt
new file mode 100644
index 0000000000..0d1f55485c
--- /dev/null
+++ b/vector/src/main/java/im/vector/app/features/roomdirectory/ExplicitTermFilter.kt
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2021 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package im.vector.app.features.roomdirectory
+
+import im.vector.app.core.utils.AssetReader
+import javax.inject.Inject
+
+class ExplicitTermFilter @Inject constructor(
+        assetReader: AssetReader
+) {
+    // List of forbidden terms is in file asset forbidden_terms.txt, in lower case
+    private val explicitTerms = assetReader.readAssetFile("forbidden_terms.txt")
+            .orEmpty()
+            .split("\n")
+            .map { it.trim() }
+            .distinct()
+            .filter { it.isNotEmpty() }
+
+    private val explicitContentRegex = explicitTerms
+            .joinToString(prefix = ".*\\b(", separator = "|", postfix = ")\\b.*")
+            .toRegex(RegexOption.IGNORE_CASE)
+
+    fun canSearchFor(term: String): Boolean {
+        return term !in explicitTerms  && term != "18+"
+    }
+
+    fun isValid(str: String): Boolean {
+        return explicitContentRegex.matches(str.replace("\n", " ")).not()
+                // Special treatment for "18+" since word boundaries does not work here
+                && str.contains("18+").not()
+    }
+}
diff --git a/vector/src/main/java/im/vector/app/features/roomdirectory/RoomDirectoryViewModel.kt b/vector/src/main/java/im/vector/app/features/roomdirectory/RoomDirectoryViewModel.kt
index 4ef38758c7..a6c4646f8c 100644
--- a/vector/src/main/java/im/vector/app/features/roomdirectory/RoomDirectoryViewModel.kt
+++ b/vector/src/main/java/im/vector/app/features/roomdirectory/RoomDirectoryViewModel.kt
@@ -42,12 +42,12 @@ import org.matrix.android.sdk.api.session.room.model.thirdparty.RoomDirectoryDat
 import org.matrix.android.sdk.api.session.room.roomSummaryQueryParams
 import org.matrix.android.sdk.rx.rx
 import timber.log.Timber
-import java.util.Locale
 
 class RoomDirectoryViewModel @AssistedInject constructor(
         @Assisted initialState: PublicRoomsViewState,
         vectorPreferences: VectorPreferences,
-        private val session: Session
+        private val session: Session,
+        private val explicitTermFilter: ExplicitTermFilter
 ) : VectorViewModel<PublicRoomsViewState, RoomDirectoryAction, RoomDirectoryViewEvents>(initialState) {
 
     @AssistedFactory
@@ -58,11 +58,6 @@ class RoomDirectoryViewModel @AssistedInject constructor(
     companion object : MvRxViewModelFactory<RoomDirectoryViewModel, PublicRoomsViewState> {
         private const val PUBLIC_ROOMS_LIMIT = 20
 
-        // List of forbidden terms, in lower case
-        private val explicitContentTerms = listOf(
-                "nsfw"
-        )
-
         @JvmStatic
         override fun create(viewModelContext: ViewModelContext, state: PublicRoomsViewState): RoomDirectoryViewModel? {
             val activity: RoomDirectoryActivity = (viewModelContext as ActivityViewModelContext).activity()
@@ -166,6 +161,17 @@ class RoomDirectoryViewModel @AssistedInject constructor(
     }
 
     private fun load(filter: String, roomDirectoryData: RoomDirectoryData) {
+        if (!showAllRooms && !explicitTermFilter.canSearchFor(filter)) {
+            setState {
+                copy(
+                        asyncPublicRoomsRequest = Success(Unit),
+                        publicRooms = emptyList(),
+                        hasMore = false
+                )
+            }
+            return
+        }
+
         currentJob = viewModelScope.launch {
             val data = try {
                 session.getPublicRooms(roomDirectoryData.homeServer,
@@ -202,11 +208,7 @@ class RoomDirectoryViewModel @AssistedInject constructor(
             // Filter
             val newPublicRooms = data.chunk.orEmpty()
                     .filter {
-                        showAllRooms
-                                || "${it.name.orEmpty()} ${it.topic.orEmpty()} ${it.canonicalAlias.orEmpty()}".toLowerCase(Locale.ROOT)
-                                .let { str ->
-                                    explicitContentTerms.all { term -> term !in str }
-                                }
+                        showAllRooms || explicitTermFilter.isValid("${it.name.orEmpty()} ${it.topic.orEmpty()}")
                     }
 
             setState {