Identifying MMORPG Bots: A Traffic Analysis Approach

MMORPGs have become extremely popular among network
gamers.Despite their success,one of MMORPG's great-
est challenges is the increasing use of game bots,i.e.,auto-
playing game clients.The use of game bots is considered
unsportsmanlike and is therefore forbidden.To keep games
in order,game police,played by actual human players,of-
ten patrol game zones and question suspicious players.This
practice,however,is labor-intensive and ine ffective.To ad-
dress this problem,we analyze the tra ffic generated by hu-
man players vs.game bots and propose solutions to auto-
matically identify game bots.
Taking Ragnarok Online ,one of the most popular MMOGs,
as our subject,we study the tra ffic generated by mainstream
game bots and human players.We find that their tra ffic
is distinguishable by:1)the regularity in the release time
of client commands,2)the trend and magnitude of tra ffic
burstiness in multiple time scales,and 3)the sensitivity to
network conditions.We propose four strategies and two in-
tegrated schemes to identify bots.For our data sets,the
conservative scheme completely avoids making false accusa-
tions against bona fide players,while the progressive scheme
tracks game bots down more aggressively.Finally,we show
that the proposed methods are generalizable to other games
and robust against counter-measures from bot developers.