well the truce about runescape is that they run on jave image supporting system. i read a little report about runescape, and i am super sure that runescape is 100% not made out of allice. and frankly, i don't even think allice is even created back then while runescape exicted.
but however, ou can make a game like runescape single player if you put in a lot of work. and you have to start simple. because for us olriginally players, runescapes grphics is way whorse than allice when it was first made, but after the upgrates it had now, it's a great game.
sorry about the grammer, im to lazy to fix it