In role playing, players adopt and act out the role of their characters. If you would like to learn more, there is a Complete Guide to Role Play, Immersion, and the Lore done especially for LotRO and its RP server, Laurelin.
The following worlds are Roleplay-Supported:
These worlds have an extra set of rules and policies to provide a more Middle-earth immersive enviroment not only for role players but also for all those who come to LotRO due to their love for the books and setting. 
In addition, the Landroval server is Roleplay-Encouraged. This world does not support the additional rules and policies that apply on the three aforementioned servers, but encourages roleplaying in a friendly environment. It is based in the USA.
A role-playing game is a type of game in which the participants assume the roles of characters and collaboratively create stories. Participants determine the actions of their characters based on their characterization, and the actions succeed or fail according to a formal system of rules and guidelines. Within the rules, they may improvise freely; their choices shape the direction and outcome of the games.
How to turn on / turn off role-playing
Type /rp on
to turn your name white and signal to other role-players that you are ready for roleplay or are role-playing.
Type /rp off
to turn your name back to yellow to signal to others that you are not role-playing.
to display your role-playing status.