B737-800 air carrier pilot reported an IRS malfunction on the First Officer flight instruments during the climb. The flight returned to the departure airport and landed overweight.

Narrative

During departure from ZZZ; the aircraft experienced an IRS (Inertial Reference System) Fault malfunction; which required crew action. FO as PF; CA as PM; aircraft established on ZZZZZ RNAV departure between FL180 and FL230. Initially; the autopilot engaged CWS (Control Wheel Steering) steering modes before disconnecting entirely as all navigation data was blanked from the FO screens. The crew recognized and communicated the faults to each other; transferred control of the aircraft to the CA; who still had information on his PFD (Primary Flight Display) and ND (Navigation Display). Autopilot was initially unable to reconnect. The crew coordinated with ATC to stop the climb and level at FL230 to work on the issue. With the CA as PF and FO as PM now; the crew completed the IRS FAULT QRH checklist; which restored data to the FO's screens. FPV (Flight Path Vector) and winds aloft data showed erroneous data on both sides (massive side slip; winds at FL230 in excess of 250 kts) so the crew determined the need to return to a field with vectors only. RNAV data could no longer be utilized for navigation. Checklist complete; the CA transferred controls to the FO and attempted to contact dispatch via crew phone. Unfortunately; the wifi system would not connect; so the CA advised dispatch via ACARS of the intention to return to ZZZ. FO coordinated with ATC for radar vectors to ZZZ and a descent; advising that the flight could not complete RNAV-specific navigation legs. The CA completed the Non-Routine Landing Considerations checklist; including notifying both the FAs and passengers of the flight status via intercom and PA; respectively. CA then completed the Overweight landing checklist in anticipation of landing at approximately 147.3k pounds.Checklists and communications complete the CA resumed PF duties because the nature of the system degradation gave priority to his screens; which would best enable a safe landing. The FO requested priority handling with ATC; and the flight landed XXC via the ILS. On approach; the crew completed the remaining checklist items; which included disabling the autopilot and autothrottles and reenabling the yaw damper. Autobrakes were inoperative due to the IRS Fault. Landing and rollout were uneventful; and the flight was escorted from the runway to the gate by vehicles as a precaution.Cause: The root cause of the event was an R IRS Fault that disabled flight data and navigation data on the FO's side of the aircraft. The crew mitigated via crew coordination; ATC assistance; TEM (Threat and Error Management); and the QRH. Recommend sustain current high standards of aircrew training; excellence in EFB (Electronic Flight Bag) and publication integration.