An addictive formula is "hard to win entirely + easy to win a little bit" examples include arcade machines/roguelike, gotcha/lootboxes/gambling, crosswords ps

An addictive formula is "hard to win entirely + easy to win a little bit" examples include arcade machines/roguelike, gotcha/lootboxes/gambling, crosswords psychologists have found that the most effective reinforcement strategy is a combination of continuous and random rewards. For example, in World of Warcraft, enemies have a small amount of gold, but only a chance of carrying a good item.