Potty

In The Sims series, potty refers to a skill that is associated with a toddler's ability to relieve his/her bladder motive through the use of a potty chair. The skill starts appearing in The Sims 2, and has appeared in all base games ever since (although it has appeared in The Sims 4 when the toddler patch was added on 12th January 2017).

Without sufficient potty skills, the toddler will still relieve his/her bladder motive with a diaper. But this comes at the expense of his/her hygiene motive. However, ageing up with a low potty skill does not affect the would-be child Sim's ability to relieve his/her bladder motive with a standard toilet.

The Sims 4
Unlike other toddler skills in The Sims 4, the maximum level a toddler can attain in the potty skill is 3 and it has no corresponding child skill.

In level 1 and below, toddlers are unable to use the potty chair by themselves and will always need supervision of a teen Sim or older. The exception is if the toddler has an independent trait.

Players can choose from two potty chairs to help train the toddlers improve their potty skills: the Practice Potty ($75) and the Monster Potty Partner ($125). Neither chair has an advantage over the other so choosing either will do exactly the same thing. Both chairs need to be cleaned from time to time otherwise other Sims may get an uncomfortable moodlet whilst they are around it.

As a toddler's potty skill level increases, they gain more abilities aimed to help them use the potty chair more effectively and confidently:
 * Level 2: toddlers can now use the potty chair unsupervised, however the toddler will not always automatically use the potty chair when their bladder motive is low. There is still a risk that the toddler may use their diapers instead causing a low hygiene motive for them and an uncomfortable moodlet to Sims around them. The player will more often than not need to direct the Toddler to the potty chair.
 * Level 3: toddlers are now more likely to automatically head for the potty chair whenever their bladder motives are low. They will also wake up from sleep in order to use the potty as opposed to their diaper. While the potty will be prefered, toddlers can still use their diapers.