Interestingly, all skills rise based on time. Players can highlight one skill at a time to initiate a timer that will run until the next higher rank is achieved. Eventually, a stage is reached where the purchase of a module becomes necessary, so complete advancement is not possible without significant funds. The amount of time it takes to raise a proficiency also depends on how your character's attributes match up to its requirements. The main purpose of skills in EVE seems to be to affect the efficiency with which players can utilize more advanced equipment and spacecraft. One notable feature is that improvement continues when a character is offline. This helps casual players to a degree, although attaining higher levels and purchasing better items still requires a great deal of monetary investment, which comes from substantial playing time.