diff --git a/src/main.rs b/src/main.rs
index 850f528..814bd7b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,12 +14,37 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 use clap::{App, Arg};
+use std::collections::HashMap;
 use std::fs;
 use std::io;
 
 mod robot;
 mod world;
 
+/// Check if the robot is in the map.
+fn check_map(r: &robot::Robot, w: &world::World) -> Result<(), String> {
+    if (r.p.x, r.p.y) < (0, 0) || (r.p.x, r.p.y) > (w.x, w.y) {
+        Err(format!("The robot {} is off map", r.id))
+    } else {
+        Ok(())
+    }
+}
+
+/// Check if the robot collide with another one at the given position.
+fn check_collisions(
+    r: &robot::Robot,
+    w: &world::World,
+    h: &HashMap<&robot::Position, &u32>,
+) -> Result<(), String> {
+    match h.get(&r.p) {
+        Some(&x) => Err(format!(
+            "The robot id: {} collided with robot id: {} in position: ({};{}) !",
+            &r.id, x, &r.p.x, &r.p.y
+        )),
+        None => Ok(()),
+    }
+}
+
 /// Parse the config file, generate the world and robot pool.
 fn parse_config(conf: String, pool: &mut Vec<robot::Robot>) -> Result<world::World, &'static str> {
     let mut lines = conf.lines();
@@ -84,4 +109,47 @@ mod tests {
         assert!(open_file("two_robots.txt").is_ok());
         assert!(open_file("test_unexisting_file.extension").is_err());
     }
+
+    #[test]
+    fn test_check_map() {
+        let mut r = robot::Robot::new(
+            0,
+            robot::Orientation::N,
+            robot::Position { x: 2, y: 3 },
+            vec!['F'],
+        );
+        let w = world::World { x: 10, y: 10 };
+
+        assert!(check_map(&r, &w).is_ok());
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_check_map_fail() {
+        let mut r = robot::Robot::new(
+            0,
+            robot::Orientation::N,
+            robot::Position { x: 2, y: 3 },
+            vec!['F'],
+        );
+        let w = world::World { x: 1, y: 1 };
+
+        assert!(check_map(&r, &w).is_ok());
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_check_collisions() {
+        let mut r = robot::Robot::new(
+            0,
+            robot::Orientation::N,
+            robot::Position { x: 2, y: 3 },
+            vec!['F'],
+        );
+        let w = world::World { x: 10, y: 10 };
+
+        let mut h: HashMap<&robot::Position, &u32> = HashMap::new();
+        h.insert(&robot::Position { x: 2, y: 3 }, &1);
+        assert!(check_collisions(&r, &w, &h).is_ok());
+    }
 }