diff --git a/core/src/errors.rs b/core/src/errors.rs
index 07fde48..bdb9e11 100644
--- a/core/src/errors.rs
+++ b/core/src/errors.rs
@@ -7,6 +7,8 @@ pub mod boards;
 pub mod messages;
 pub mod threads;
 
+pub mod marks;
+
 pub mod auth;
 pub mod authors;
 pub mod files;
diff --git a/core/src/errors/marks.rs b/core/src/errors/marks.rs
new file mode 100644
index 0000000..71c6c5a
--- /dev/null
+++ b/core/src/errors/marks.rs
@@ -0,0 +1,10 @@
+use eva::data;
+
+#[data]
+pub struct NoSuchTag {}
+
+#[data]
+pub struct NoSuchGenre {}
+
+#[data]
+pub struct NoSuchBadge {}
diff --git a/core/src/requests/games.rs b/core/src/requests/games.rs
index 0a4acc3..b67984c 100644
--- a/core/src/requests/games.rs
+++ b/core/src/requests/games.rs
@@ -1,6 +1,6 @@
 use crate::{
     errors,
-    types::{Patch, True, author, file, game},
+    types::{Patch, True, author, file, game, mark},
 };
 
 use std::collections::HashMap;
@@ -23,9 +23,9 @@ pub mod update {
         pub description: Patch<Option<game::Description>>,
         pub slug: Patch<game::Slug>,
         pub thumbnail: Patch<Option<file::Id>>,
-        pub genres: Patch<game::Genres>,
-        pub badges: Patch<game::Badges>,
-        pub tags: Patch<game::Tags>,
+        pub genres: Patch<mark::Genres>,
+        pub badges: Patch<mark::Badges>,
+        pub tags: Patch<mark::Tags>,
         pub screenshots: Patch<game::Screenshots>,
         pub published: Patch<bool>,
     }
@@ -53,9 +53,9 @@ pub mod search {
     #[data]
     #[derive(Default)]
     pub struct Marks {
-        pub tags: Logic<game::Tag, 16>,
-        pub genres: Logic<game::Genre, 16>,
-        pub badges: Logic<game::Badge, 16>,
+        pub tags: Logic<mark::Tag, 16>,
+        pub genres: Logic<mark::Genre, 16>,
+        pub badges: Logic<mark::Badge, 16>,
     }
 
     type SortKey<K> = (K, game::Id);
@@ -141,6 +141,10 @@ pub mod create {
         pub description: Option<game::Description>,
         pub thumbnail: Option<file::Id>,
         pub author: author::Id,
+        #[serde(default)]
+        pub tags: mark::Tags,
+        #[serde(default)]
+        pub genres: mark::Genres,
         pub slug: Option<game::Slug>,
         pub vndb: Option<game::VndbId>,
         pub release_date: Option<game::ReleaseDate>,
@@ -165,8 +169,8 @@ pub mod get {
 
     #[data]
     pub struct Marks {
-        pub tags: HashMap<game::Tag, str::CompactString>,
-        pub badges: HashMap<game::Badge, str::CompactString>,
+        pub tags: HashMap<mark::Tag, str::CompactString>,
+        pub badges: HashMap<mark::Badge, str::CompactString>,
     }
 
     #[data]
diff --git a/core/src/requests/marks.rs b/core/src/requests/marks.rs
index 964d58d..8bc40df 100644
--- a/core/src/requests/marks.rs
+++ b/core/src/requests/marks.rs
@@ -1,4 +1,4 @@
-use crate::types::game;
+use crate::types::mark;
 
 use eva::{array, data, str};
 
@@ -18,7 +18,7 @@ pub mod add_tag {
 
     #[data]
     pub struct Ok {
-        pub id: game::Tag,
+        pub id: mark::Tag,
     }
 
     #[data(error, display("_"))]
@@ -35,7 +35,7 @@ pub mod add_badge {
 
     #[data]
     pub struct Ok {
-        pub id: game::Badge,
+        pub id: mark::Badge,
     }
 
     #[data(error, display("_"))]
@@ -52,7 +52,7 @@ pub mod list_genres {
 
     #[data]
     pub struct Ok {
-        pub genres: array::ImmutableHeap<game::Genre, MAX>,
+        pub genres: array::ImmutableHeap<mark::Genre, MAX>,
     }
 
     #[data(error, display("_"))]
@@ -69,7 +69,7 @@ pub mod list_badges {
 
     #[data]
     pub struct Ok {
-        pub badges: Vec<TextEntry<game::Badge>>,
+        pub badges: Vec<TextEntry<mark::Badge>>,
     }
 
     #[data(error, display("_"))]
@@ -86,7 +86,7 @@ pub mod list_tags {
 
     #[data]
     pub struct Ok {
-        pub tags: Vec<TextEntry<game::Tag>>,
+        pub tags: Vec<TextEntry<mark::Tag>>,
     }
 
     #[data(error, display("_"))]
diff --git a/core/src/types/game.rs b/core/src/types/game.rs
index 4b3173b..a618a8e 100644
--- a/core/src/types/game.rs
+++ b/core/src/types/game.rs
@@ -1,18 +1,6 @@
 use eva::{array, data, int, str, str::CompactString, time::Date};
 
-use crate::types::{author, entity::define_eid, file, slug, user};
-
-#[data]
-#[derive(Default)]
-pub struct Tags(pub array::ImmutableHeap<Tag, 64>);
-
-#[data]
-#[derive(Default)]
-pub struct Genres(pub array::ImmutableHeap<Genre, 64>);
-
-#[data]
-#[derive(Default)]
-pub struct Badges(pub array::ImmutableHeap<Badge, 64>);
+use crate::types::{author, entity::define_eid, file, mark, slug, user};
 
 #[data]
 #[derive(Default)]
@@ -100,9 +88,9 @@ pub struct Game {
     pub publication: Option<Publication>,
 
     pub screenshots: Screenshots,
-    pub tags: Tags,
-    pub genres: Genres,
-    pub badges: Badges,
+    pub tags: mark::Tags,
+    pub genres: mark::Genres,
+    pub badges: mark::Badges,
 }
 
 #[data(copy)]
@@ -129,17 +117,8 @@ pub struct Votes(pub u32);
 define_eid! {
     /// ID of the game.
     pub struct Id(Game);
-
-    /// ID of the tag.
-    pub struct Tag(Tag);
-
-    /// Game badge.
-    pub struct Badge(Badge);
 }
 
-#[str(newtype, copy)]
-pub struct Genre(pub slug::LowerSlug<15>);
-
 /// Estimated time to read.
 #[int(u8, 0..=100)]
 pub enum TimeToReadHours {}
diff --git a/core/src/types/mark.rs b/core/src/types/mark.rs
new file mode 100644
index 0000000..4adf478
--- /dev/null
+++ b/core/src/types/mark.rs
@@ -0,0 +1,26 @@
+use eva::{array, data, str};
+
+use crate::types::{entity, slug};
+
+#[data]
+#[derive(Default)]
+pub struct Tags(pub array::ImmutableHeap<Tag, 64>);
+
+#[data]
+#[derive(Default)]
+pub struct Genres(pub array::ImmutableHeap<Genre, 64>);
+
+#[data]
+#[derive(Default)]
+pub struct Badges(pub array::ImmutableHeap<Badge, 64>);
+
+#[str(newtype, copy)]
+pub struct Genre(pub slug::LowerSlug<15>);
+
+entity::define_eid! {
+    /// ID of the tag.
+    pub struct Tag(Tag);
+
+    /// Game badge.
+    pub struct Badge(Badge);
+}
diff --git a/core/src/types/mod.rs b/core/src/types/mod.rs
index a3dc5eb..414ea29 100644
--- a/core/src/types/mod.rs
+++ b/core/src/types/mod.rs
@@ -6,6 +6,8 @@ pub mod board;
 pub mod message;
 pub mod thread;
 
+pub mod mark;
+
 pub mod author;
 pub mod user;