—Hey, there! Just so you know, we have revised and improved our prestige classes, as well as come up with another one: the Shadow Dancer. You can check them out in Arcane Emporium, Vol. 6.—
Prestige classes were introduced in 3rd Edition as a means to further individualize a character. They had prerequisites that could be met by characters of different classes, essentially acting like a more exclusive multiclassing option.
In 5th Edition, many of these prestige classes (such as the arcane archer and the eldritch knight) have become backgrounds or archetypes of the base classes listed in the Player’s Handbook. There are benefits and drawbacks to this approach; while it makes for greater diversity in the individual classes, it also, paradoxically, restricts player options. Rather than being able to balance their shapechanging and spellcasting abilities, for example, a druid is forced to either follow the circle of the land or the circle of the moon. A fighter must choose between learning useful combat manoeuvres through the battle master archetype or learning spells as an eldritch knight. A wizard used to be able to become an arcane archer after achieving a high enough base attack bonus. Now they have to multiclass several levels into rogue. Same thing for fighters and rangers who want to become assassins, and could previously do so with a clever distribution of skill ranks.
The result of these changes is that players are less easily able to subvert standard fantasy tropes and are, instead, pushed to make characters that conform to established archetypes. While I find that this is, by and large, a fair trade-off for the versatility 5th Edition characters generally gain anyway, some character options I have been playing with still require that characters not be restricted by their base class choice.
To illustrate my point, I present my take on 5th Edition prestige classes, complete with two prestige class options: the guild mage and the lycanthrope.