Combat is improved upon, with the V.A.T.S. system being updated with several new V.A.T.S.-specific attacks, and a number of kill animations being made for several of the game's melee weapons. Players can use the iron sights on firearms in the game, with the exception of certain larger guns and some energy weapons.
The third-person perspective in the game was redesigned to be more "over the shoulder" than it had been in Fallout 3.
The Character Creation section of the game was refined to take less time than Fallout 3, with players able to skip the tutorials and proceed across the Wasteland once their character is set up. The option to make any last minute changes to their character occurs when the player steps beyond the boundaries of the starting location of Goodsprings.
More Perks were added to the game to provide greater options for improving the player's characters upon leveling up.
The Perk system itself changed, allowing a Perk at every other level instead of every level like in earlier games in order to prevent the player from having an overly powerful character early in the game.
More weapons were added to the game, including the 9 mm Pistol, the Single Shotgun, Powder Charges, Dynamite, Trail Carbine, and Grenade Launcher.
The "Big Guns" and "Small Guns" skills are consolidated into one skill: "Guns".
A new skill, Survival, is introduced. This skill impacts how much health is restored by food and drink. Skills have a larger effect on conversation choices; whether a dialogue option will succeed or fail is shown up front, and entirely dependent on Skill level, rather than both skill and chance as was the case in Fallout 3. Players can receive a temporary boost to a skill by reading a skill magazine corresponding to it, which can be found around the Mojave Wasteland or purchased from vendors, the effects of which can be further enhanced by certain Perks.
Players can gamble. They can do this by visiting casinos, buying chips with the three major currencies in the games, and playing either blackjack, slots, or roulette within them. Players can also play a card game called Caravan, which was specifically designed for the game and has its own rules, and can be played with certain people outside of the casinos.
Crafting and modding
Although players could craft items in Fallout 3, these items were limited to a few unique weapons. With New Vegas, crafting was expanded to allow the creation of food, drink, drugs, and ammunition along with unique weapons. Crafting can be done at workbenches, reloading benches, and campfires, and requires specific components as well as a sufficient skill level; for instance, cooking food at campfires requires the player to have a sufficient Survival skill level to do so. Some special items cannot be made until their recipes/schematics are found. Players can harvest plants to use in recipes, similar to Bethesda's The Elder Scrolls series. In addition to crafting, players can also modify weapons with special firearm modifications. Such modifications can improve the rate of fire or the size of the magazine, or add a mounted telescopic sight to allow for greater range. Modifications for firearms often require either scavenging for them in the Mojave or purchasing them from vendors.
Reputation
Because of the large number of factions created for the game, developers reintroduced the reputation system that was first used in Fallout 2 and had been absent in Fallout 3. Much like Karma, a player's standing with a faction can change depending on how they interact with them and what decisions they make. If, for example, players help a faction, their reputation with them improves in all locations controlled by that faction; opting to kill their members will cause a loss of reputation. The type of reputation the player has with each faction affects how non-player characters (NPCs) behave towards them; a good reputation might make completing some quests easier, provide discounts with the faction's vendors, and cause faction members to offer gifts; a bad reputation may lead to the faction refusing to help the player or attacking them on sight, or sending assassins after the player.
Companions
Companions in New Vegas are much easier to control than in Fallout 3, through the use of the "Companion Wheel". Through the Wheel, players can switch a companion's tactics in combat, including their behavior and how they attack, as well as dismiss them, treat them for injuries, and access their inventory. Players are capable of having two companions with them at any one time – one humanoid and one non-humanoid. Companions can confer a unique Perk or advantage and have the opportunity to be improved by completing a special quest related to them. They can also be sent directly to a player's home upon being dismissed rather than returning to their original location.
Hardcore mode
An optional difficulty setting included in New Vegas is the Hardcore mode, which delivers more realism and intensity to the playing environment. While the standard adjustable difficulty level settings only affect combat difficulty, Hardcore mode adds statistics and encourages the player to consider resource management and combat tactics. Game director Josh Sawyer stated that the mode was inspired by several different Fallout 3 mods. In this mode, the following occurs:
All healing items, including food and water, do not heal the player instantly but work over a short period of time. RadAway also takes time to gradually decrease radiation poisoning, rather than instantly.
Stimpaks can no longer heal crippled limbs. Players must either use Doctor's Bags, sleep in an owned or rented bed, use the chem Hydra, or visit a doctor to heal limbs.
Ammunition and caps have weight, reducing the amount that can be carried.
Players must eat, drink, and sleep, to avoid starvation, dehydration, and exhaustion; failure to do so confers a steady decrease in certain skills and eventually leads to death if untreated.
Companions can be killed upon being reduced to zero hit points, rather than losing consciousness.
Completing the game on this mode (from start to finish as the mode can be turned on at any point during the game) results in either an achievement (Xbox 360/Steam) or trophy (PlayStation 3) being awarded.
