Just earlier this week, Riot - the minds behind the accomplish MOBA League of Legends - has details on their blog how they deals with cheaters in the game. This blog post has shown to readers the ways developers take action against botters and scripters - two most common types of cheat in game.
Of course, at the end, cheaters will have to face with the "Ban hammer" (A slang for being banned from the game). But, the main problem is how to detect cheaters, and to discourage the cheating actions in game. For Riot's case, they have formed an anti-cheat team to deal exclusively with this kind of problem.
According to the developers, the worst kind of cheat in League of Legends right now is scripting. Using a cheating program, players can auto target their abilities, auto execute combos to destroy the opponents, auto dodge skills, or tracking opponent's cooldown. All these advantages ruins the gameplay experience of players, and can outright makes the game become unfair.
As we can see in the above graph, the percentage of cheaters got reduced over time, with every ban wave remove a large percent of cheaters. These statistics above showed that, sometimes, the dev just need to implement harsh punishment to all kinds of cheating, in order to produce a better gaming environments.
Along with that, in these types of games, cheating is not the sure win ticket for players.
Even with all those advantages, the average win rate for cheaters right now is around 55%, and still getting lowers over time. Because of that, the advantages cheating provide is not worth it anymore, since the risk associated with cheating is way too high. Some cheaters, in order to avoid detection, have to add more delays to their auto actions - which in turn lower their advantages.
Also, at the higher level of the games, all the advantages that cheating provide cannot bridge the gaps in skill between players. You cheat, but still can not win. You got bored, and think of cheating as a waste. As a plus, your account was banned because of that. All those actions are removing the motivation for cheating, which in turns, reduce the number of cheaters.
At the end of the day, when the motivations are gone, you will not bother cheating anymore.