play a part in
Synonym discussion
Sense: idiom/1
While all three alternatives describe taking part in something, they differ in emphasis and register. 'Play a part in' suggests being one factor among several, without specifying the size of the contribution. 'Contribute to' places more focus on a positive, concrete effect — you contribute to a fund or a result. 'Be involved in' is the broadest and most neutral option; it simply states participation without implying influence. 'Have a hand in' is informal and often implies hands-on or deliberate involvement — for example, 'a few designers had a hand in the new logo.' Use 'play a part in' when you want to show something was one of multiple causes or contributors.
Etymology
The idiom 'play a part' comes from the world of theater, where an actor 'plays a part' (performs a role) in a play. By the 18th century, it had spread into general use to mean 'fulfill a function' or 'be a factor' in any situation, not just on stage.