Chemistry

Chemistry was introduced in the Nightlife expansion of The Sims 2.

Sims have always been attracted to each other fairly easily so far. Only a massive divergence of interests would harm two Sims' relationships, but even that could be overcome with a bit of work.

Not anymore. Although love can still blossom under any circumstances with enough effort, Sims now get two turn-ons and one turn-off from a limited list. If two Sims match up, they will have positive chemistry. This will make certain social interactions available earlier in the relationship, and make it easier for all interactions to pass. Conversely, if two Sims are incompatible, they will have negative chemistry, and actions will fail more often.

Each teen, adult and elder Sim has two turn-ons and one turn-off. Turn-ons and turn-offs are designed to make relationships easier (or harder) to achieve. Sims with compatible turn-ons/offs will have lightning bolts in their relationship panels (maximum of 3). Sims in community lots can scope crowds to find those special Sims.

Sims made before Nightlife get a potion called the ReNuYu Porta-Chug, which allows the Sim to change their turn-ons and turn-off, so they are not locked into randomly chosen ones.

Turn-ons and turn-offs can also be changed by using the ReNuYuSenso Orb, which is an aspiration reward. If University is installed, college Sims can change their turn-ons and turn-off, as well as their aspiration, when they finish their Sophomore year. A Sim's turn-ons and turn-off can also be changed with SimPE.

It is not possible to select chemistry based on gender, age, or skin color. However it is possible to indirectly select a chemistry for gender by making the Sim like or dislike make-up and/or beards, and Sims can be made to dislike/like elder Sims by selecting grey hair.

List of Turn-on/offs

 * Hair
 * Black, Blond, Brown, Red, Grey, Custom, Facial Hair


 * Clothing
 * Swim Wear, Underwear, Formal Wear


 * Accessories
 * Glasses, Jewelry


 * Makeup
 * Makeup, Full face make-up


 * Fitness
 * Fat, Fit


 * Smell
 * Cologne, Stink


 * Life state (Must have associated expansion pack)
 * Vampirism
 * Lycanthropy, Plantsimism, Zombiism, Robots (Must also have Bon Voyage)
 * Witchiness


 * Good at Skill (Must have Bon Voyage)
 * Cooking, Cleaning, Creativity, Body, Logic, Charisma, Mechanical


 * Employment (Must have Bon Voyage)
 * Unemployed, Hard Worker