How do I make a timer for a grenade?

I am making a grenade and want a timer, so it doesn't explode as soon as it hits the ground. What script is used for this?

Take a look at WaitForSeconds. Then, assuming you want the timer to start from when the grenade is thrown, do something like:

  1. Instantiate the grenade
  2. Wait for as many seconds as you want (using the above method)
  3. Play an explosion sound, spawn a particle effect, destroy the gameObject, etc

In future, you should try scripting it yourself and then post if you have problems (that you can't find a solution for by searching). Otherwise you'll usually have your question tagged as 'write-my-code', and generally they're ignored.

Instantiate the grenade...

Destroy(gameObject, 5);

Particle Effect the grenade...

Well i will be happy to right your code. But this may not work. But go ahead and try it.

function Update ()
    yeild WaitForSeconds(5);
    Destroy (gameObject)

If this does not work for you search up yeild wait for seconds but this should work. You have to code your own particle emiter though. So you got to do a bit coding yourself too you know.