The Fallout world is massive and even outside of the main campaign there are so many things going on that the world feels real and alive. Lots of the buildings are actually enter-able and usually have something unique and interesting to discover.

There is quite a lot of loot to be found in the game. Weapons and armor are scattered all over the wasteland map as well as contained in many dungeons. Unique and legendary loot can be found by defeating certain types of enemies as well. Overall this gives a good incentive to keep exploring and defeating bad guys, all in the search of getting that better piece of gear.

There are quite a lot of different enemies found in the game, ranging from Super Mutants to Feral Zombies to Blood Bugs. Each has their own weakness and strength, which asks the player to constantly adjust their fighting style due to what is being thrown at them at the time.

Users can find all sorts of mods at Nexus Mods, which will help expand and change the gameplay making for an infinitely playable game due to the vast amount of options available.

There are a bunch of companions to find in the game, starting with a dog. Each companion has their own skills that can help the player in the game, such as the dog can find hidden items in the world and retrieve them. As the player progresses in the game, more companions can be found, though only one can be used at a time. They can be easily swapped out for those that would like to see what each offers easily. Even better is the player does not have to use one if they do not like, which may make the game a little more tough, but some may enjoy that challenge.

You can can find all sorts of mods at the Bethesda website, giving you the freedom to change the parts of the game you don't like. This includes interface adjustments, graphical improvements, additional quests, and many other things.

The perk/skill system is presented as a large grid of perks the player can pick from. As the player levels up, they earn skill points which can then be used to gain perks in this large grid. The choices are pretty vast with seven different areas that perks can be picked from. This is called the S.P.E.C.I.A.L. system, standing for Strength, Perception, Endurance, Charisma, Intelligence, Agility and Luck. Each of these seven skills have their own row of perks, of which those perks cost a certain amount of skill points to use. A total of 70 perks give the player a lot of choice and customization to their character.

If you want to make a character centered around being a sharp shooter, there are perks for that, if you want to focus on creating a tank of a character that can plow through enemies with little damage, there are perks for that too. This way anyone can create a very original character on each playthrough.

Fallout has typically used a slowed down time based gun mechanic called VATS, which works as an assisted shooting and aiming mechanic that allows one to pick the body parts of an enemy to target in slowed down time. This system is present in Fallout 4, but the first/third person gunplay has been improved so much over previous titles that it is not as necessary to use anymore (as it once was). Basically the gunplay works so well in this game that players can run and gun with ease, though the VATs system is still there for those that prefer it. Either way, the gunplay feels and plays well, no matter the system used, which makes for a varied design that feels solid and enjoyable.

Base building is a way that the player can collect components in the world to then use them to make their own base for equipment and supplies. There is also an interesting aspect where the player can attract NPCs in the game to their base in order to create a settlement (basically a small town of people). This can only be done in particular spaces in the game though. The rest of the base building mechanics can be used anywhere the player wants and in any style they like. If you want to build a floating base that only you can access, this can be done. Want to build a giant towering structure that goes as high as you like, you can do that too. Really there is very little limiting the player from creating anything they imagine for their base. This can make for a solid distraction from the main story of the game as the player can sink as much or as little time into it as they like.

There are several types of baseline weapons that can be heavily modified. For example you can convert a laser rifle into a sniper by modifying the barrel, scope and stock. It's really fun to scrap weapons you find for components to beef up your favorite guns.

The main storyline is well written featuring the main character looking for redemption and their lost son. Expanding on that is the many side quests available that flush out the world that is Boston in this post apocalyptic future.