Roleplaying Gametype
The Roleplaying game type is a user created "custom" game in which players are expected to take on the role of a character or leader from the game's scenario or, in other words, role play. Due to the roleplay, sometimes the aim of players may not be to win in the traditional sense of conquering all their enemies. The scenario largely dictates how the game is to be played.
Gameplay
Common roleplay aspects may include:
Scenario
Scenarios are designed by the host to give players a context in which to roleplay. This should include things such as time period, world, scope and roles. These parameters give players the guidelines with which to play the game.
Optional rules for RP (roleplay) games include diplomacy, also known as diplo, public enemy, Old English (or any other language, dialect or accent, just for fun).
Diplo
While Diplo is often part of an RP game (or vice versa) the two do not need to go hand in hand. In other words, both types are not mutually exclusive but they do not need to be paired together. Many players often conflate these two aspects of game play but this often causes confusion among players who do not carefully read the game description.
Other
Common settings are "no fog" or "slight fog", so as to know if someone really did blitzkrieg. All cards are often enabled to allow for interesting storyline twists to occur in the game.
Also most Diplomacy-games are Multi-Day Games, so everyone can react easily and unstressed and because Diplomacy-Games often have many Players. But also some are Real-Time with a high Boot-Time.
Most hosts make the game a practice game.
Most hosts also use custom scenarios, if they aren't able to use custom scenarios, they usually choose manual distribution.