If you're spending that much, spend £600-700 on a decent desktop PC and get a tablet/iPad/laptop to presumably write up notes and for it's portability. If you gave more of a decsription of what was needed it may be more helpful, but if you just want to write up notes and play games, get a PC and then another device to write notes etc. Personally I'd go for a tablet, unless you have reason to need the laptop or iPad, as it's cheaper.
You don't need to spend more than £700 or anything like £1000+ to play minecraft and world of warcraft, they're not AA games and run perfectly (100+ fps) on my £400 computer, with monitor and windows 10 included in price... A £1400 laptop is overpriced as hell, the dell XPS 15 you could build in a PC for £800 easy and still have £400 left over for a laptop to take to lectures, until you give more of a brief I believe a dual combo will be better