WooHoo

WooHoo is an interaction used in The Sims series, starting from The Sims 2, as a euphemism for sexual intercourse. WooHoo interactions can be carried out between two Sims, regardless of gender, that have to be romantically interested in each other. During a WooHoo, firework effects will appear along with bouncy effects in The Sims 2, or heart effects in The Sims 3 and The Sims 4. WooHooing will boost the social and fun motives of both Sims. While Sims can WooHoo without trying for a baby, and without risk of pregnancy, the "Try for Baby" action is also considered a WooHoo.

A WooHoo is a special event in a Sim's life in The Sims 2. If cinematics are enabled, there will be a comic animation involving the first time a Sim WooHooes with another. Sims will earn a memory of each Sim they WooHoo with. If The Sims 2: University is installed, they will also receive the very first WooHoo memory. Oddly, WooHoo in The Sims 2 does not affect the Sims' gender preference.

Sims usually desire to do a public WooHoo. Doing a public WooHoo will grant a special memory for the engaging Sims or a special moodlet and stride. WooHooing in The Sims 4 will provide a moodlet that affects their emotions, and it's possible for them to experience a good or bad WooHoo.

There is no WooHoo in The Sims. Introduced in The Sims: Livin' Large, Sims can "play in bed," as an allusion and a precursor to WooHoo. Sims could also "play" in the two-person hot tubs from The Sims: Hot Date and The Sims: Vacation. 

Where Sims Woohoo
The WooHoo interaction is possible in these locations:

The Sims 2

 * Bed
 * Hot tub
 * Changing booth (public WooHoo)
 * Car
 * Photo booth (public WooHoo)
 * Elevator (public WooHoo)
 * Tent
 * Sauna (public WooHoo)
 * Hammock
 * Helicopter
 * Walk-in closet

In The Sims 2, Public WooHoo is a form of WooHoo that is done using the specific indicated objects on a community lot. Sims may have wants to have Public WooHoo. Public WooHoo gives a specific memory, and other Sims on the lot will react to it.

The Sims 3

 * Bed
 * Rabbit holes (must tour inside one first) such as military base, theater, and science lab, among others
 * Tent
 * Sarcophagus
 * Time machine
 * Hot tub
 * Elevator
 * Actor trailer
 * Shower
 * Treehouse
 * Haystack
 * Photo booth
 * Box of Mystery
 * Magical wardrobe
 * Fairy house
 * Gypsy wagon
 * Sauna
 * Igloo
 * Pile of leaves
 * Hot air balloon
 * Murphy bed
 * All-in-one bathroom
 * Underwater cave
 * Resort tower
 * Jetpack
 * Bot workshop
 * ZEPHYR
 * Restorable junk car
 * Gondola

As of The Sims 3: Late Night, the game recognizes a public WooHoo, which is done outside the Sim's home. When they do this, Sims will get the "Stride of Pride" moodlet and do a fancy walk. Doing a WooHoo inside a photo booth is considered a public WooHoo, even if it's done at home.

The Sims 4

 * Bed
 * Rocket ship
 * Observatory
 * Tent
 * Hot Tub
 * Sauna

Try for baby
A male and female Sim can alternatively initiate the "Try for Baby" interaction to conceive a baby. In The Sims 2, the female Sim must be on her home lot or controllable on a community lot. In The Sims 3, the female Sim does not need to be on her home lot to try for a baby.

Trying for a baby carries a chance of conception depending on where it was done.
 * 20% in a photo booth
 * 25% in a hot tub
 * 40% in a sauna  and all-in-one bathroom
 * 50% in a clothing booth and other places not listed here in The Sims 3.
 * 55% in a time machine and underwater cave
 * 60% in a bed
 * 65% in an elevator
 * 75% in a bed and sarcophagus
 * 100% on the Heart-shaped bed

Additional chance of conception is increased by certain conditions, as following.
 * +20% when Sims try for baby in full moon
 * +25% for each Sim who has Fertility Treatment lifetime reward or "A Twinkle in the Eye" moodlet, from Procreation Elixir. The effect doesn't stack if one Sim has both the lifetime reward and the moodlet.
 * +50% for each Sim who has the "Magic in the Air" moodlet, from talking to baby's breath in Arboretum.
 * +100% for each Sim who has the "Feeling Fertile" moodlet, from genie wish for large family.

In The Sims 2, "Try for baby" is not possible for an adult female who is less than 5 days away from becoming an elder. Once an adult female is 5 days away from becoming an elder, she may still be able to "Try for Baby" until 11 a.m. the next day. In The Sims 2: University, "Try for Baby" is not possible for a young adult female. Young Adults can "Try for Baby" in The Sims 3 and Young Adult females are more fertile than Adult females; i.e. there is a greater chance for twins and triplets to occur. In The Sims 3, if a Sim becomes pregnant directly before becoming an elder, then the process of aging is simply suspended until after the baby is born.

If the lot already has 8 controllable Sims on it, the "Try for Baby" option will not appear. Zombies, Mummies, Servos, and SimBots do not have the "Try for Baby" interaction. Without hacks or mods, only male/female couples can try for a baby. A male between the ages of Young Adult and Elder can impregnate a female.

Without cheats, male Sims can only be impregnated by aliens. This can occur if they "Stargaze" with the more expensive telescope at night, though it is very unlikely to happen. However, if FreeTime or later is installed, any Sim who has Knowledge as their primary aspiration, and who has enough Lifetime Aspiration points, can choose Summon aliens as an aspiration benefit. A Sim with this benefit can use any telescope to attempt to summon aliens, and will have a higher chance of being abducted. Therefore, an adult male Sim with this benefit can, more or less, try for an alien-hybrid baby.

The "Try for Baby" option does not exist in The Sims Medieval. In The Sims Medieval, Woohoo between two Sims of the opposite gender always carries a chance of pregnancy.

Gender and Age compatibility
The following table shows the compatibility of various age groups and genders for WooHoo/baby interactions. Note: when referring to trying for a baby, the table only states the possibilities for the interaction.

As with all other romantic interactions, blood relatives and teens and younger are automatically prevented from WooHooing although there are hacks that allow both groups to do this, with the exception of Sims younger than teen. In The Sims 4, teens are able to "mess around" with other teens, an implication of WooHoo. The differences are that teens will not get a WooHoo-specific moodlet and they will not change to sleepwear when they mess around on bed.

Because of its wide-ranging implications, WooHoo is never autonomous. In The Sims 2, there is a mod called Autonomous Casual Romance, which can be found on Simbology. This allows Sims to WooHoo and even Try For Baby on their own, though the player can still forbid the latter if they want. Another mod on Simbology allows same-sex couples to Try For Baby; the Sim that initiates the action will be considered the "mother."

Pets
Pets can WooHoo in order to breed (producing a litter of up to 4 puppies or kittens), but they require a Sim that has a good relationship with at least one of the pets to direct them, and the pets obviously must have a good relationship. The gestation period is approx. 72 game hours, just like Sims. If pets have a bad relationship with the other pet, they will refuse the action and go off on their own for a bit sometimes.