Guns is the skill for basic ranged attacks in T3. In this sense, a bow, sling, or slingshot is a gun. So is a grenade, because it does not inflict damage because of the hitting power of your thow.
Thowing weapons that do damage by impact are governed by MartialArts.
Guns follow the basic combat Rules in most ways, but there are some special cases applicableonly to guns.
Aiming
A special maneuver available to guns is aiming. Select a target that you can shoot at and spend a shot aiming; your next Guns attack against that target gets a +1 action value bonus. You can spend up to three consecutive rounds aiming, for a total bonus of +3. You may not move between aiming and firing.
Autofire
Included from MultipleTargets
Autofire is a special case of area attack that allows you to hit several times against the same target or different targets in the same general area. You must fire three rounds with each attack, and may not reload during the attack sequence.
If firing on several targets, use the normal area effect rules.
When attacking one target several times, resolve each attack separately, but there is a -2 penalty on each successive attack. For each attack beyond the first, you must expend one additional shot hosing the target down, but you perform all these attacks simultaneously. You also get one "free" attack against each friend or bystander in your line of fire, with no penalty.
Once a target starts to use ActiveDefense, he gets to apply the Dodge bonus against all your attacks, as they all come in the same shot.
Covering Fire
Covering fire is a special variant of Active Defense. By shooting an at opponent, you force him to keep his head down, reducing his change to succeed at any action and stopping any movement that is not under cover. Covering fire is a one-shot defensive action that can be used to defend either yourself or someone else. Unlike a normal active defense, it only affects one small group of enemies, who must be grouped close together. It also spends a lot of ammo; three rounds per attacker covered. Like other Active Defense it lasts for the current shot only.
It is possible to ignore covering fire. In this case, the Active Defense and movement hindrance is ignored, and the covering fire is instead resolved as a standard guns attack. This is a separate attack against each target that elected to ignore the covering fire. This is the tactic typically chosen by animals, mindless zombies, and other targets unaware of how guns work. The advantage to the user of covering fire is that you get to make a 1-shot atatck against all of them.
Covering fire does not work if your target is himself under cover and doing something that does not require him to stick his head out. Nor does it work if there is something near your target that you want to avoid - it is wild fire, and the risk of collateral damage is too great to use it in such situations.