they beg, whine, tick people off and comment negatively on basically anything that isn't runescape.
Not all runescape players are Runecapers, they average player will usually play, forget and play again, while the Runescaper will play, play, brag, rant, play,play and be a jackass, or whack off.
They are heard talking about runescape 80% of the time. other times they are being jackasses or ranting on another game, that's probably better.
hanging around runescapers are like hanging around cock blockers or twat swatters, commonly turning the very flirty (or normal) conversation into something really gay or embarrassing, provided you are not a runescaper.
Greg: yo, i made this awesome cake
hot chick: That looks great
RS: THE C@K3 1 M@D3 0N RUN3SC4P3 IS 1000000 T1M3S B3TT4R!1!
(the cake i made on runescape is 1000000 times better)
hot chick: yeah... i should go....
Greg: WAIT NO!!! DX