4. Deep Character Customization
This one has two meanings. First is skins, which alter the appearance of your champion, and are not necessary incredibly deep, but a very cool touch that adds a nice layer of customization to your favorite champion. The other meaning here are the rune and mastery systems. Mastery will be immediately familiar to anyone who has played an MMO in the last 10 years. It looks like a talent tree, but features generic upgrades so it can be used for several different champions. You can also save several different mastery set-ups for your different champions. The same goes for runes, but the rune system works a little differently. You unlock hexes on a grid as you level up, and can drop runes of of the appropriate type into each slot. Runes are persistent, so no need to worry about buying loads of them, when you switch rune setups, your runes from the previous set up are removed or moved to the proper place in the new setup. Runes and champions can be purchased with in-game currency, called Influence Points, or real money currency, called Riot Points. Skins can only be purchased with Riot Points. Which brings me to the next point...