Some games are fully chance based. Some games are fully skill based.
But some games are both, and life is like this too.
The problem is when one is disguised as the other. Often chance is disguised as skill, to make the player try to figure out how to do better. The other case, where skill is disguised as chance, is far rarer.
Most games involve both chance and skill. A game that is totally based on luck is merely a lottery. However, even games where luck and ability are mixed can be deceptive. Most often, chance is disguised as skill, but it can go the other way as well.
Carnival games are renowned for this deception. They present the player with an apparent reliance on ability. Yet the ability is often fed into a chaos system, where slight variations of the input create vast differences in the output. This is luck cleverly disguised as skill. Many computer games do the same, with lottery mechanics hidden behind apparent tests of player ability.
Just as devious (but far less common) are games of skill disguised as pure chance. This often occurs in racing games, where if you press the throttle button at exactly the right time you receive a boost off the starting line. Games rarely exhibit this deciet, since most people would be rather miffed if their finely honed reflexes were dismissed as chance.
Children often have difficulty distinguishing luck and skill. The games “War” and “Chutes and Ladders” are common examples. Many children will honestly believe they have the ability to influence their position, and that they are “better” than other people at these games. The clever disguises we put on skill and chance in games for adults demonstrates that this childish thought process is not easy to grow out of.
When playing and designing games, be sure to discern what is skill and what is random chance. Both are good in their place, but they can be frustrating or harmful when dressed to confuse.