ScriptProjectile

using UnityEngine;
using System.Collections;

public class ScriptProjectile : MonoBehaviour {

    //Information about our projectile... how much damage? How much should it push
    //the victim on height? how much force should add on the push? how fast should it go?
    public int ProjDamage = 1;
    public float ProjHeight = 2f;
    public float ProjForce =10f;
    public float ProjSpeed=15f;

    //This time is to make sure it won't be running forever if it doesn't hit anything.
    //If you want to limit the range of the projectile set this to a lower value.
    public float selfDestructTime=3f;

    //It needs a DealDamage script, so we'll store one here.
    private DealDamage DoDamage;
    //We'll use this bool to check if we have been initiated by the player.
    private bool Initiated=false;

    void Start() {
        //Create a Deal Damage Component for us.
        DoDamage = gameObject.AddComponent<DealDamage>();
    }

    //This function will be called from the player to start our projectile.
    public void Initialize() {
        Initiated=true;
        //This will start our countdown to self destruction
        StartCoroutine(selfDestruct(selfDestructTime));
    }

    void FixedUpdate () {
        //If it has been initiated by the player
        if(Initiated) {
            //Tell the Rigid Body to move forward at the desired speed
            rigidbody.MovePosition(rigidbody.transform.position+(transform.forward*ProjSpeed*Time.deltaTime));
        }
    }

    //This function runs for each collider on our trigger zone, on each frame they are on our trigger zone.
    void OnTriggerEnter(Collider other) {
        //If it hasn't been initiated by the player, just stop here.
        if(!Initiated) {
            return;
        }
        //If the object colliding doesn't have the tag player and is not a trigger...
        if(other.gameObject.tag!="Player" && !other.isTrigger) {
            //If it's a rigid body, tell our DealDamage to attack it!
            if (other.attachedRigidbody) {
                DoDamage.Attack(other.gameObject,ProjDamage,ProjHeight,ProjForce);
            }
            //If it isn't we still probably want to destroy our projectile since it has a collider, so destroy it wether it is a rigid body or not.
            Destroy(this.gameObject);
        }
    }

    //Coroutine to wait for the set amount of seconds and destroy itself.
    IEnumerator selfDestruct(float waitTime) {
        yield return new WaitForSeconds(waitTime);
        Destroy(this.gameObject);
    }
}