diff --git a/src/main.rs b/src/main.rs
index 68460dc..843f0bd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -59,18 +59,15 @@ fn create_hash_map(pool: &Vec<robot::Robot>, hash: &mut HashMap<robot::Position,
     }
 }
 
-/// Generate random instructions.
-fn gen_random_instructions() -> String {
+fn gen_world(pool: &mut Vec<robot::Robot>) -> Result<world::World, String> {
+    let w = world::random_world();
     let mut rng = rand::thread_rng();
-    let n = rng.gen_range(5, 10);
-    let mut instructions = String::with_capacity(n);
-    const CHARSET: &[u8] = b"LRF";
-    for _ in 0..n {
-        let l = rng.gen_range(0, CHARSET.len());
-        instructions.push(CHARSET[l] as char);
+    let x = rng.gen_range(2, 10);
+    for i in 0..=x {
+        let r = robot::Robot::new_random(i + 1, w.x - 2, w.y - 2)?;
+        pool.push(r);
     }
-
-    instructions
+    Ok(w)
 }
 
 /// Parse the config file, generate the world and robot pool.
@@ -207,15 +204,27 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 .takes_value(false)
                 .help("Generate random world"),
         )
+        .arg(
+            Arg::with_name("random")
+                .short("r")
+                .long("random")
+                .takes_value(false)
+                .help("Generate random world"),
+        )
         .get_matches();
 
-    let raw_conf = open_file(matches.value_of("file").unwrap_or("two_robots.txt"))?;
-
     let mut robot_pool: Vec<robot::Robot> = Vec::new();
-    let mut world: world::World = parse_config(raw_conf, &mut robot_pool)?;
-    world = match matches.is_present("random-world") {
-        false => world,
-        true => world::random_world(),
+    let world = match matches.is_present("random") {
+        true => gen_world(&mut robot_pool)?,
+        false => {
+            let raw_conf = open_file(matches.value_of("file").unwrap_or("two_robots.txt"))?;
+            let mut world: world::World = parse_config(raw_conf, &mut robot_pool)?;
+            world = match matches.is_present("random-world") {
+                false => world,
+                true => world::random_world(),
+            };
+            world
+        }
     };
 
     let mut hash: HashMap<robot::Position, u32> = HashMap::new();
diff --git a/src/robot.rs b/src/robot.rs
index 79c9877..d8c37e2 100644
--- a/src/robot.rs
+++ b/src/robot.rs
@@ -17,6 +17,21 @@ impl Robot {
     pub fn new(id: u32, o: Orientation, p: Position, i: Vec<Instruction>) -> Robot {
         Robot { id, o, p, i }
     }
+    /// Create new random `Robot`.
+    pub fn new_random(id: u32, posx_max: i32, posy_max: i32) -> Result<Robot, String> {
+        let mut rng = rand::thread_rng();
+        let x = rng.gen_range(2, posx_max);
+        let y = rng.gen_range(2, posy_max);
+        let inst = gen_random_instructions();
+        let instructions: Vec<Instruction> = instructions_from_string(inst)?;
+        let o: Orientation = rand::random();
+        Ok(Robot {
+            id,
+            o,
+            p: Position { x, y },
+            i: instructions,
+        })
+    }
     /// Apply given instruction to a `Robot`.
     pub fn execute_instruction(&mut self) {
         match self.i.pop() {
@@ -100,17 +115,18 @@ pub struct Position {
     pub y: i32,
 }
 
-/// Check if instructions list is valid.
-pub fn is_instructions(s: &str) -> bool {
-    for c in s.chars() {
-        match c {
-            'F' => continue,
-            'R' => continue,
-            'L' => continue,
-            _ => return false,
-        }
+/// Generate random instructions.
+fn gen_random_instructions() -> String {
+    let mut rng = rand::thread_rng();
+    let n = rng.gen_range(5, 10);
+    let mut instructions = String::with_capacity(n);
+    const CHARSET: &[u8] = b"LRF";
+    for _ in 0..n {
+        let l = rng.gen_range(0, CHARSET.len());
+        instructions.push(CHARSET[l] as char);
     }
-    true
+
+    instructions
 }
 
 /// Check if a robot is piouff.