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Effectively, monsters with a level adjustment become multiclass character when they take class levels. Add a monster’s level adjustment to its Humanoids and Class Levels to get the creature’s effective character level, or ECL. Monsters suitable for play have a level adjustment given in their statistics. Some creatures have strange innate abilities or great physical power, and thus are questionable at best as characters (except in high-level campaigns).
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Creatures who have an Intelligence score of 2 or lower, who have no way to communicate, or who are so different from other PCs that they disrupt the campaign should not be used.
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While every monster has the statistics that a player would need to play the creature as a character, most monsters are not suitable as PCs.
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