Yes, I'm a noob but I'm good at Warcraft map making.

So.. is there anyway to make a bullet?
This is what I need:
1. Can you detect where you casted a spell or ordered a unit to attack?
2. How would you do it so that if a unit collides with the "bullet" it dies?

Thanks.

1. No
2. The answer to that is complicated. You could only make a bullet virtually and represent it with a unit or an effect

If you're interested in putting some effort into higher level techniques I can try to teach you them. I suggest taking a look at the map, Elementa.

The best way is to make a unit=bullet and then center a location over the certain unit and then make a trigger when player 1 brings anyunit to bullet location kill player 1 unit and bullet.

@Kaias: Couldn't Dark Swarm detection work?
@Ashamed: I don' think I can find a disabled flying unit that goes fast.

Dark swarm would work as the detection setting, as of fast units its kinda hard to make bullets in sc! >< I would say use a scorge!

One option is using dark swarm to mark the target and a scourge or interceptor as a bullet. Dark swarm can be detected as a ragular unit, just remember that it is always owned by Player 12 (Neutral).

I have a problem though, I want the unit that walks around and stuff to be a Ghost..

they have their own guns

Even though this probably was intended as a joke only, it is a wise choice - keep it simple. There are no simple solutions to your problem if you want your unit to be a ghost.

That might be the way to go unless you want to make a direction grid= which way the unit points and then like a hotkey thing that always sends the scorge the way the unit is pointing, i did a system like that once. This is very hard though but i did make a map on the direction grid which was quite simple but its only for up down left and right diagnals work but not well

It wasn't a joke, I meant it as you interpreted. He hasn't given enough specification as to why he doesn't just keep the default unit attack action.

I also suggest checking out Waypoint Casting- to see if it fits your needs.

You can use EUDs to detect when a unit fires. Halloween Priest uses that for it's ammo system.

EUDs are way too hard to get right, but probably the best way. You have to detect cooldown of the unit, and if it is greater than 0, then you started the attack animation. If you use a slow attacking unit like marine or ghost, you can then stop the animation and prevent it from actually shooting. I highly recommend you NOT try this, as it will more than likely not get done, due to the great difficulty involved in EUDs.

An alternative is "shooter" where you use the ghost to attack an observer you control. When the observer dies, anything over that point can be detected, so you aim, then shoot. It's pretty userunfriendly. The way to detect when a bullet collides (or observer in this case) is to center a location over the observer always, and when you bring another unit to that location, you can destroy it, or whatever.

Check out RUSH in the DLDB for another shooter system.

How do I supposedly move the observer?

Left click using your mouse on the observer. Then move the cursor to where you want to shoot. Then right click using your mouse and the observer will go there.

or you could just move the observer over stuff and it would kill it.

you could theoretically make an observer over every unit in range, then have them constantly ordered to the units position. Sort of like a "lock on" idea.

Seriously though we need to know more about what kind of bullet you are trying tn do, or why you want a bullet.

Ok.
Player clicks on an area
Bullet goes there. If a unit is in the way, kill it.