"Mizter T" wrote

The Javelin service from St Pancras - Stratford - Ebbsfleet was and
remains a pivotal part of the overall games transport plan. It's not clear
how much of the SE Highspeed service will run during the games,
but the Javelin service will take priority. In this context I have every
expectation that the Games Travelcard will cover travel on the Javelin - my
understanding is that it will.

A passenger from (say) Ashford will presumably need to buy a ticket to
somewhere in order to use the Javelin service to access the Olympic site at
Stratford. At the moment it seems that potential Olympic ticket purchasers
are not being told whether 'somewhere' is Ebbsfleet or Stratford or St.
Pancras or even somewhere else. It certainly isn't clear to me, and I
consider myself reasonably clued-up on One-day Travelcards; perhaps I'm not
quite so clued-up on Period Travelcards. It's not yet clear to what extent
a 'Games Travelcard' differs in validity from the sundry varieties of
inboundary/outboundary Day/Period Travelcards.

The OP is asking a similar question re travel from Maidenhead or Castle
Cary; the answer to that is also unclear.