 Additionally, such RPGs as "", "", and "Deus Ex" have all been identified as containing certain modes of play that are mostly non-violent.This concept is also explored in the higher difficulty levels of the "Thief" series.In 2015 the fan-funded indie RPG "Undertale" allowed players to choose whether or not to use violent methods, in a story that includes both explicit and subtextual commentary on the nature of violence in videogames.