Linear gameplay is in stark contrast with the recently popular style known as open-ended gameplay, or sandbox gameplay. The plot is already pre-determined, and is communicated through regular cutscenes that usually occur before and after a level. It is still widely popular because of it facilitates the telling of a story through scripted events, and can create intense and fun scenarios for the player to experience. Games such as Halo 3, Call of Duty 4, and Half Life 2 are well known for employing this style. This style is mainly popular in FPS and RTS games, as well as on-rails games such as rail shooters and side-scrollers, occasionally making an appearance in the RPG genre, where open-ended gameplay is more common.