The Sims 2: Nightlife alters the base game through both broad-scope changes, such as the introduction of a dedicated "downtown" area composed primarily of community lots, and more complex alterations to how Sims act and react.
Nightlife revamps the base game's romantic interactions by introducing a "chemistry" system, where Sims are more or less attracted to each other based on personality, aspiration, and newly introduced "turn-ons" and "turn-offs". Potential turn-ons and turn-offs include hair color, body shape, and supernatural characteristics.
Nightlife introduces a timed and scored dating
minigame. A Sim on a date must fulfil as many of their partner's wants (short-term goals set by their aspiration) as possible, while avoiding their fears (which lose aspiration points when fulfilled). If they succeed at fulfilling wants, their date score will increase and their partner will reward them with gifts; should the date fail, they will instead be "rewarded" with flaming bags of fecal matter. A platonic "social outing" system is also introduced, using the same basic mechanics as dates. The dating system is intertwined with
Nightlife expanded recreation options. Sims are able to visit specialized downtown subneighborhoods containing community lots such as bars, clubs, restaurants, and bowling alleys, and dates and outings are intended to occur in such areas.
The Sims 2 has an aspiration system, where Sims have one of five primary life goals (Knowledge, Family, Fortune, Romance, or Popularity) that determine their wants and fears.
Nightlife introduces two new aspirations, Pleasure and Grilled Cheese. Pleasure Sims are hedonistic and interested in "the kinds of things downtown offers"; their wants revolve around things such as dining out, going on successful dates, and
DJing, while their fears include being rejected for social opportunities. The "socially awkward and nutritionally dicey" Grilled Cheese aspiration can only be acquired from a mishap with a reward object called the ReNuYuSenso Orb that allows Sims to change their aspirations; Grilled Cheese Sims are hyperfixated on the preparation and consumption of
grilled cheese sandwiches. They have special interactions such as the ability to cook such sandwiches at any time of day, rather than be restricted to lunch preparation, and to "Talk About Grilled Cheese", which rarely endears them to other Sims.
Nightlife both introduces new objects and alters how players interact with them. It is the first game in the series where Sims are able to drive cars; according to producer Tim LeTourneau, this feature was added primarily for "storytelling" and increasing verisimilitude, rather than as a fundamental change to the game's carpool- and taxi-focused transit. Other objects introduced in the expansion pack include poker tables, bowling alleys, and karaoke machines. Following the introduction of supernatural Sims in
University,
Nightlife is the first
Sims installment to include vampires. Two non-player vampires, known as Grand Vampires, inhabit each downtown and are recognizable by their "classic vampire garb". Sims that befriend the Grand Vampires can ask to be bitten, becoming vampires themselves; these Sims can go on to create more vampires. During the nighttime, vampires' motives do not decay, relieving them of needs such as eating or sleeping; however, their motives decay during daytime, which becomes rapid enough to kill them quickly if they go outdoors in sunlight. Vampires do not age or cast a reflection in mirrors, and are able to fly (by turning into a bat) rather than walk.
Nightlife vampires are based on a more "classical" aesthetic of vampirism than vampires in
The Sims 3 and
The Sims 4; writers have described
Nightlife vampires as inspired alternately by "medieval" or "Victorian" aesthetics, while the later games have more modern-appearing vampires that lack some of
Nightlife visibly inhuman characteristics, such as blue-tinted skin.
Nightlife vampires are able to reproduce, but unlike their counterparts in later games, they do not pass down vampirism as a genetic characteristic. They are also able to be hybridized with other supernatural Sims, such as zombies. ==Soundtrack==