The Division of an Entity in Three
Later, when the Bible was translated into Latin (the Vulgate), appeared the name Lucifer as a translation of Morning Star (the planet Venus), in Isaiah 14:12. But if we take only this allusion we are out of context, because Isaiah 14:1-23 speaks about Babylon and its king, being the Morning Star the Babylonian king, of godly status, being his symbolic divine parents Bel and Ishtar (associated with the planet Venus); this can be seen by reading any Babylonian cuneiform text, but by the time of the translation of the Bible and the subsequent biblical exegesis that took the text as a comparison with the Devil these cuneiform clay tablets and their translation were not available, and the mythology and customs the Israelites had learnt during their captivity in Babylon had been forgotten. Early Christian tradition interpreted the word and the entire paragraph referring to Satan, his fell of grace, and the moment he was thrown from Heaven, identifying this name with him, and Lucifer became another name for Satan; due to the Christian dogma and popular tradition, so it will remain.
But this was not enough. Christian demonologists later turned Satan, Lucifer, and Beelzebub into different entities, with a different rank in the hellish hierarchy. According to who wrote on them, Lucifer or Satan used to be the chief of all demons. Why? There is no answer; nobody gave an explanation for this.
Perhaps the fact that many ignorant people (as instructions was uncommon for most population) was interrogated during the witch trials collaborated, because one person could answer "my master is Lucifer", another "I made a pact with Satan", etc., not having these people knowledge of the different names of the Devil, and being sometimes suggested the name to them by the interrogator, depending on how he called the Devil in that moment. But this cannot explain that demonologists that supposedly had this knowledge (many of them were priests, with important studies) continued using these names for different entities coexisting in the same Hell.
It could also be supposed that this might have been an attempt to establish a hellish trinity with the same person, as the Christian Trinity has three persons in one with Father, Son and Holy Ghost.
In Christian Tradition
However, in Christian tradition but not in Christian demonology, Satan, Lucifer and Beelzebub mean "the Devil", and Prince of this World, The Beast and Dragon (and rarely Serpent or The Old Serpent) use to be elliptic forms to refer to him. The Enemy, The Evil One and The Tempter are also elliptic forms to name the Devil. Christian tradition has many nicknames for Satan, but not demonology.
It must be noted that Mephistopheles is used by some people to refer to the Devil, but it is a mere folkloric custom, and has nothing to do with Christian demonology and Christian tradition. Prince of Darkness and Lord of Darkness are also folkloric names, although Lord of Darkness tends to be incorporated to Christian tradition.
In role-playing games
In the Dungeons & Dragons universe, devils are known in some versions of the game as baatezu; these devils are hostile to the demons, who are known in the same system as tanar'ri. The two factions of fiends, of which there are many different subtypes of each, fight a "Blood War" among themselves. See also fantasy bestiary.
In other games
It has always been rumored that The Devil and his demons communicate with humans through the Ouija game. The general public is divided about this subject: Some support the afore mentioned theory, while others say that humans move the game's triangle with a hand and claim to be communicating with outer spirits.
See Also