Aimed at demystifying probability theory, this text provides a brief and non-technical introduction to the subject. Employing few formulas, Rudas uses intuitive but precise descriptions and examples to explain procedures in probability as a springboard for understanding the concepts of expectation, variance, continuous distributions, normal distribution, chi-squared distribution, and the applications of probability theory in research practice. This book gives researchers and students a solid foundation for understanding probability, and can serve as a supplement in general statistics courses.