As you get ready for the awesome, post-apocalyptic goodness that is Fallout 4 on Xbox One, don’t forget that for a limited time it comes with its direct predecessor, Fallout 3 – available first on Xbox 360 and then on Xbox One after November 12 when Xbox One Backward Compatibility becomes available. Whether you pre-order or purchase the game physically, digitally, or as part of the Xbox One Fallout 4 Bundle, you’ll definitely want to pick up Fallout 4 now if you haven’t already to grab your free copy of Fallout 3 (limited time offer).

While both Fallout 3 and Fallout 4 are thematically similar, Fallout 3 remains one of the seminal steps in the role-playing genre, revolutionizing a series that was previously PC-based by introducing it to the Xbox 360 console. This modern classic took a massive, open-world approach, and included a slew of new, clever gameplay systems designed to work smoothly on both PC and Xbox 360. After great success and a large fan base on Xbox 360, Fallout 3 will now be available on Xbox One through Backward Compatibility for the newest generation of gaming.

First among these systems was the Vault-Tec Assisted Targeting System, or V.A.T.S., which has become an icon of the Fallout series since. While Fallout 3 is presented as a traditional first-person shooter, the truth is that its combat system goes far deeper than that. Whenever you’re aiming, the game is calculating a variety of factors: how good your gun/ammo is, how high your accuracy stats are, and what kind of defenses your enemy is packing. Most games keep this info in the background, but triggering V.A.T.S. changes that.

Toggling V.A.T.S. stops time, and presents you with a series of percentage points and highlighted targets on the enemy’s body: limbs, torso, head, even their weapon. Hitting each of these requires a tradeoff: The torso is easier to hit, but does less damage, and doesn’t (usually) come with any critical bonuses. Hitting a limb or a weapon is tougher, but may disable it if you do it right. And then, of course, the head is a kill shot – but it’s also the hardest to hit, especially at long range. V.A.T.S. takes all those familiar FPS shooting mechanics and adds in an RPG element, putting fine-tuned control at your fingertips.

Of course, V.A.T.S. returns in Fallout 4, too, and since you get Fallout 3 for free with Fallout 4, now is a great opportunity to check out the continuity between the two systems. In Fallout 4, V.A.T.S. has been even more refined to work seamlessly with the shooting – not stopping time entirely, but slowing it down and flowing directly from the player’s other shooting. The difference in Fallout 4, too, is that using V.A.T.S. is limited by a rechargeable bar; you can only use it so often, but the good news is that you can choose when and where a critical hit will score, so it’s even more powerful than it used to be.

Thanks to Xbox One Backward Compatibility, you only need a single console to experience V.A.T.S. and the rest of the awesomeness of both Fallout 3 and Fallout 4, with no extra work. Heck, you can even use the excellent Xbox One Elite Wireless Controller, if you really want to have a leg up on the old-school wasteland before you jump into Fallout 4’s post-nuclear Boston. However you choose to play, you’ll get the most out of your Fallout experience on Xbox One.