The Sims 4 Pregnancy Guide, From How To Have Babies, Twins, Triplets ...

How to influence multiple births and have twins or triplets in The Sims 4

If you are pregnant, the odds of multiple births are as follows:

• Single baby: 89%
• Twins: 10%
• Triplets: 1%

Since you'll need to have a Sim give birth to triplets to unlock the 'Triple Play' Achievement/Trophy (more on that specifically below), that's a lot of waiting for the random number generator to smile on you.

As with gender, there's no foolproof way to ensure a multiple birth; but there are a number of things you can do to increase its likelihood.

Fertility boosts are most effective if they are used shortly before the 'Try for Baby' interaction. The following factors can influence your odds of having twins or triplets in The Sims 4:

• 'Fertile' Reward Trait: Purchased from the Satisfaction Reward Store for 3000 Satisfaction Points, 'Fertile' increases the chance of a successful 'Try for Baby' for the Sim who possesses the trait (whether they are the birth parent or not), as well as greatly increasing the chances for twins or triplets. This is the only method of influencing multiple births that is available in the base game.
• 'On Ley-Line' Lot Trait: Sims who conceive on a lot with this trait should expect multiple births the majority of the time, though single births are still a small possibility. (Requires City Living expansion pack.)
• Elixir of Fertility: Sims with Level 10 in the Herbalism skill can brew this elixir recipe. Sims who consume it will have an increased chance of conceiving twins or triplets. (Requires Outdoor Retreat game pack.)
• Fertility Massage: Sims with Level 9 in the Wellness skill can give this massage, which results in the 'Fertility Boost' moodlet for the Sim who receives it. Engaging in 'Try for Baby' while the moodlet is active (12 in-game hours) boosts the odds of a multiple pregnancy. (Requires Spa Day game pack.)
• Wishing Well: Sims have the chance of getting a baby instantly added to their household, but, as with most wishes, there's also a chance of a negative, and in this case, their household will get a ghost child. (Requires Romantic Garden Stuff.)

How to get the 'Triple Play' achievement/trophy The Sims 4

Though the above will help with multiple births in general, the 'Triple Play' achievement specifically requires you to have triplets born into one of your Sim families in order to unlock - so you might want some additional tips.

Using all the above-mentioned methods in combination will almost guarantee a multiple birth, but unfortunately there's no way to specifically increase the odds of getting triplets as opposed to twins.

Even with all the fertility modifiers in use and the chances of a single birth almost eliminated, a pregnancy will still only result in triplets about 10% of the time.

However, these odds are still much better than the 1% base chance of having triplets randomly. If you want to focus on getting this achievement, choose a Sim family and begin by applying the 'Fertile' reward trait to both prospective parents. Then, depending on what expansions you have installed, you can make use of the 'On Ley-Line' lot trait, Elixir of Fertility, and Fertility Massage to further boost your chances of success.

It might take a few tries (and a lot of twins) to get this achievement, so be sure to age up and move out the older kids regularly to make room for your Sims' next attempt.

Alternative Method: If you really want the 'Triple Play' achievement but aren't too fussy about how you get it, there's a quicker route if you have Cats & Dogs installed. Breeding your pets (using the 'Encourage to Mate...' interaction) results in litters of one to three puppies or kittens at a time. Unlike human Sims, pets can expect twins from 50% of pregnancies, while single babies and triplets have a 25% chance each at the base rate.

Applying the 'Breeding Ground' lot trait increases the odds of multiple pet births even further. At the time of writing, the game considers cat or dog triplets to be good enough, and will unlock the achievement.