The　initial　behavior　of　multi-principal　element　alloys　(MPEAs)　is　crucial　to　understanding　their　deformation　mechanism.　However,　its　orientation　dependence　remains　poorly　understood.　The　initial　plastic　behavior　of　three　typical　crystal　planes　(100),　(110)　and　(111)　of　FeNiCr　MPEA　was　investigated　by　nanoindentation　experiments,　molecular　dynamics　(MD)　simulations　and　density　functional　theory　(DFT)　calculations.　Our　novel　findings　reveal　that　the　initial　plastic　behavior　of　FeNiCr　MPEA　is　highly　orientation-dependent.　Specifically,　the　(111)　plane　has　the　highest　initial　yield　load,　and　(110)　plane　exhibits　the　smallest　width　of　displacement　burst.　This　is　related　to　the　number　of　activated　slip　systems　and　the　evolution　behavior　of　dislocation　structure　under　different　crystal　orientations.　These　differences　would　not　lead　to　different　incipient　mechanisms　and　activation　volumes.　For　the　first　time,　MD　simulations　not　only　clarify　that　the　dislocation　nucleation　load　is　the　decisive　factor　for　the　initial　yield　load　but　also　disclose　that　the　incipient　behavior　of　(111)　orientation　is　more　sensitive　to　the　lattice　distortion　(LD).　In　addition,　DFT　results　unravel　that　intrinsic　LD　promotes　dislocation　nucleation　by　triggering　heterogeneous　distribution　of　charge　density.　Finally,　the　orientation　dependence　of　incipient　behavior　in　FCC　FeNiCr　MPEA　shares　similarities　with　conventional　metals　and　other　FCC　MPEAs,　but　differs　from　BCC　MPEAs　due　to　their　distinct　slip　systems.　The　key　findings　of　this　paper　deepen　our　understanding　of　the　incipient　behavior　of　MPEAs.　©　2025　Elsevier　Ltd