diff --git a/src/mock.rs b/src/mock.rs
index b5928cb..cb44fa0 100644
--- a/src/mock.rs
+++ b/src/mock.rs
@@ -118,8 +118,8 @@ pub fn item() -> Item {
 
 pub fn room() -> Room {
     Room {
-        id: "a".to_string(),
-        palette: "9".to_string(),
+        id: 10,
+        palette_id: 9,
         name: Some("cellar 7".to_string()),
         tiles: vec![
             "0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"1l".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),
@@ -176,8 +176,8 @@ pub fn game_default() -> Game {
         ],
         rooms: vec![
             Room {
-                id: "0".to_string(),
-                palette: "0".to_string(),
+                id: 0,
+                palette_id: 0,
                 name: None,
                 tiles: vec![
                     "0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),"0".to_string(),
diff --git a/src/room.rs b/src/room.rs
index 3f6a423..900b198 100644
--- a/src/room.rs
+++ b/src/room.rs
@@ -1,9 +1,9 @@
-use crate::{Exit, ExitInstance, Instance, mock, Position};
+use crate::{Exit, ExitInstance, Instance, mock, Position, from_base36, to_base36};
 
 #[derive(Debug, Eq, PartialEq)]
 pub struct Room {
-    pub id: String,
-    pub palette: String, // id
+    pub id: u64,
+    pub palette_id: u64, // id
     pub name: Option<String>,
     pub tiles: Vec<String>, // tile ids
     pub items: Vec<Instance>,
@@ -15,9 +15,9 @@ impl From<String> for Room {
     fn from(string: String) -> Room {
         // todo handle room_format?
         let mut lines: Vec<&str> = string.lines().collect();
-        let id = lines[0].replace("ROOM ", "");
+        let id = from_base36(&lines[0].replace("ROOM ", ""));
         let mut name = None;
-        let mut palette = "0".to_string();
+        let mut palette_id = 0;
         let mut items: Vec<Instance> = Vec::new();
         let mut exits: Vec<ExitInstance> = Vec::new();
         let mut endings: Vec<Instance> = Vec::new();
@@ -28,7 +28,7 @@ impl From<String> for Room {
             if last_line.starts_with("NAME") {
                 name = Some(last_line.replace("NAME ", "").to_string());
             } else if last_line.starts_with("PAL") {
-                palette = last_line.replace("PAL ", "").to_string();
+                palette_id = from_base36(&last_line.replace("PAL ", ""));
             } else if last_line.starts_with("ITM") {
                 let last_line = last_line.replace("ITM ", "");
                 let item_position: Vec<&str> = last_line.split(' ').collect();
@@ -70,7 +70,7 @@ impl From<String> for Room {
             }
         }
 
-        Room { id, palette, name, tiles, items, exits, endings }
+        Room { id, palette_id, name, tiles, items, exits, endings }
     }
 }
 
@@ -123,13 +123,13 @@ impl ToString for Room {
 
         format!(
             "ROOM {}\n{}{}{}{}{}\nPAL {}",
-            self.id,
+            to_base36(self.id),
             tiles,
             if self.name.as_ref().is_some() { format!("\nNAME {}", self.name.as_ref().unwrap()) } else { "".to_string() },
             items,
             exits,
             endings,
-            self.palette
+            to_base36(self.palette_id)
         )
     }
 }