Knowledge that can be applied to real life in a skill-based, practical sense would likely be limited mostly to the "simulator" games as @Fuckingjoke noted; truck driving, flight, mechanic. "Edutainment" is how they can be classed I believe. Those are primarily interactive educational material in a more relatable medium for the modern age over strict 'book-learning' and are quite useful for helping to become familiar with a subject without the costs and dangers involved with the real thing. And of course that can also be used simply for entertainment. However, they would likely be best used in an educational sense as an introductory or supplemental to hands-on education in those areas. I expect few could jump right from a few thousand hours exclusively 'playing' a truck driving or flight sim to operating a real rig on the road or plane in the air without any issues, let alone 'playing' a mechanic sim and then rebuilding a transmission in a garage first try without any issues. There are of course other game types -especially MMORPGs- which can help from a financial/economical sense in that many games involve currency, trading and markets and can provide some useful skills in that arena. They are quite useful for gaining understanding of supply and demand, of different markets of necessities and frivolities, as well as how different services relate to and even rely upon each other through systems thinking. Some players treat MMORPGs as market simulators and just stand in front of traders/auction houses all day who become the equivalent to millionaires without having ever left the starting area from day 1. There are also the more philosophical games that present complex situations and poke at questions regarding the nature of consciousness and of reality itself, which can also help with understanding other people and the world and thus useful in real world interactions with people and our environment.