The Sims 3: Late Night is an expansion pack, which means that you'll need a copy of The Sims 3 in order to play. Late Night features a brand-new neighborhood for your Sims to explore--a small built-up "city" called Bridgeport, which appears to be modeled after San Francisco and Los Angeles. Bridgeport features high-rise apartment buildings where your Sim can rent a modest studio apartment (living the real city life) or purchase an expensive penthouse. While high-rise apartments have naturally limited space (you won't be able to build outside of your apartment, obviously), there are plenty of new sexy furniture options, including an absurdly large wall-sized fish tank.
New home décor is always exciting, but what's the point of having a sexy apartment if you don't have a sexy Sim to live there? Late Night comes with a lot of new Sim customization options, including clothing, hairstyles, and body sliders. The clothing and hairstyles are mostly what you'll need to live the fast-paced urban lifestyle--skintight t-shirts and tousled hairstyles for the guys, and racy clubbing tops and messy up-dos for the girls.
The two new body sliders will be a welcome addition for a lot of Sim fans--a "muscle definition" body slider, which allows you to customize how much muscle definition your Sim has (the most muscular Sims look a lot like Jersey Shore's "The Situation"), and a breast slider for, um, adjusting the size of your Sim's chest (without putting on more weight). Hey, we'll just assume Bridgeport is like every other big city--sexy, elite, and totally superficial. And yes, moving the breast slider all the way over to the right makes your Sim look like she's had a little artificial enhancement.
Once your Sim is all decked out with his/her six-pack/boob job, they're ready to hit the town. Bridgeport features a number of hoppin' night spots--from little dive bars to ritzy, upscale lounges and clubs. Most of the venues don't open until later (anywhere from the late afternoon to the early evening), and each one has its own requirements for admission. Some of the venues--mostly the dive bars and the lower-end clubs--are open to the public right away (and feature red velvet ropes sans bouncer), while others are much more exclusive. Bouncers can be bribed, flirted with, or impressed into letting you in, though some won't even talk to you unless you have a certain celeb status.
There are a number of new opportunities for your Sims to take advantage of in Late Night--for example, your Sim can play as a celebrity, a rockstar, or even a vampire. Each path features its own perks and challenges, but choosing at least one is necessary in order for your Sim to gain admittance to the most exclusive late-night venues.