RuneScape is a game that needs no introduction - ever since it redefined the Massively Multiplayer Online RPG genre upon its release in 2001, Jagex's fantasy opus has captivated an entire generation with its immersive yet accessible adventure action. It's planning a substantial expansion of RuneScape's capabilities in the coming months.
Both versions of RuneScape will offer crossplay, making it possible for to access the same character on both PC and mobile.
Old School RuneScape will land on mobile this winter, and RuneScape will arrive shortly after, in 2018. There are spells, monsters, and quests-typical RPG stuff. These are full-fledged mobile clients of the existing game, not a separate version. With MMORPGs being so time consuming and grind heavy, the ability to, say, lay in bed for an hour before you go to sleep and get in a little extra questing could go a huge way to improving players' overall experience. It's a free-to-play game, so you can check it out right now with no risk.
The current main version of RuneScape is sometimes known as RuneScape 3 (it's the third major revision). You can see some screenshots from the mobile versions below; the first four images are from Old-School RuneScape, while the last is from RuneScape. It's still maintained by the developers, too. As a bonus, a mobile port of the old-school version of the game will be released this Winter, though an exact date was not announced for either game. There is also a potential new audience that might have never played RuneScape before, much less even heard of it, and these mobile clients will be the entry point to a real, full-fledged MMORPG on mobile. You can register your interest on the RuneScape site.