If the game falls closer to the skill-based end of the spectrum, then it's sufficiently skill-based to not count as gambling. If the game predominantly relies on chance with only some elements of skill, then it is considered gambling.
Cash-based tournaments in games of skill are not considered gambling because the generally accepted definition of gambling involves three specific things: (1) the award of a prize, (2) paid-in consideration (meaning entrants pay to compete) and (3) an outcome determined on the basis of chance.
