Jagex Account Guardian (or JAG) is an optional security feature that provides an enhanced level of security to help RuneScape players protect their account. Once enabled JAG limits in-game access for your account to specific devices, which have been authorised by you.
Devices can be added temporarily or permanently, as well as being removed at any time using your registered email account and some security questions.
With JAG enabled, unrecognised devices will be blocked from accessing RuneScape and will need to go through some security checks before access is granted, even if the current password is known.
I'm still checking this out, but this may make account trading safer.
Edit: The way I see it, this is basically a new set of recovery questions that can't be changed (unless you remove JAG) and has to be entered every time you want to log in on a computer you haven't registered on the account.
I'm pretty sure the account can still be recovered by the original owner even if you only put JAG on it after he sold it to you. This doesn't seem to change anything, except for preventing people from getting hacked.














