You should plan for the STAR for your arrival gate. Once close to the airport ATC will vector you to a location to fix on the localizer for the approach you'll use. A real life example would be a flight from KSLC to KDEN. Say, for example, your flight plan is LEETZ2 CHE TOMSN4. TOMSN4 is the Northwest gate into Denver. The FMC will display legs inbound on TOMSN4 all the way to FQF and then display "ROUTE DISCONTINUITY" after that. You would fly your flight plan. Say for example that Denver is landing on 16R and this is the runway they'll want you to use. At some point on the arrival, they'll vector you off of the TOMSN4 to a fix to pick up the 16R localizer. For example, aroundTOMSN you may get vectored over to NIWOT. At this point you'd select ILS 16R as the approach. You'd put NIWOT into the first page, first line of the RTE, and you'd be on the ILS 16R all the way in. Basically to sum up, you plan to use the STAR for the direction in which you'll arrive knowing that once there, ATC will vector you to the appropriate route for the runway they want you to use. David Barry