The Google-owned firm - which is one of the most popular websites on the internet - has taken the decision in light of so-called "challenges" that have led to severe injuries and, in some cases, even deaths.
Despite this, there remain concerns over the potentially ambiguous nature of YouTube's new rules on pranks.
A section of the site's FAQ segment reads: "YouTube is home to many beloved viral challenges and pranks.
"That said, we've always had policies to make sure what's funny doesn't cross the line into also being harmful or dangerous.
"Our Community Guidelines prohibit content that encourages dangerous activities that are likely to result in serious harm, and today clarifying what this means for dangerous challenges and pranks."
Meanwhile, a study in 2018 found that three-quarters of children in the UK under the age of five now has access to a tablet, smartphone or computer.
The research - conducted by Childwise, a market research company - shows that three in four kids in the UK had access to a connected device, while the majority of three- and four-year-olds had their own tablet or PC.
Research manager Jenny Ehren explained: "The increasing use of connected devices by preschoolers this year may reflect growing access to on-demand services, especially subscription-based options such as Netflix, which has quickly risen through the ranks over the last three to four years.
"Their list of favourite programmes is becoming more varied. And whilst many are drawn from across the different preschool channels, we are beginning to see more references to content exclusively available on YouTube and paid-for streaming services."