"Advanced Dungeons & Dragons" loosened the restrictions on race and class combinations, although non-human races often had restricted choices among classes and maximum levels they could reach in a class. Additional classes that had first appeared in supplements and articles in "The Strategic Review" magazine were included as base classes. The "Player's Handbook" also introduced the Bard as a sixth base class; however, its usage in 1st edition was more akin to what would be called a prestige class in later editions, as it was not a legal choice for a starting character. Instead, a character had to start as a Fighter, change classes to a Thief, and finally switch classes once more to become a Bard.