One　of　key　factors　in　designing　high-performance　alloys　is　to　understand　their　incipient　behavior.　To　get　detailed　real-time　atomic　scale　evolutions　of　multi-principal　element　alloys　(MPEAs)　during　nanoindentation　incipient　yielding,　molecular　dynamics　(MD)　simulations　were　carried　out.　Emphases　are　given　to　the　effects　of　lattice　distortion　(LD)　and　chemical　short-range　ordering　(CSRO)　on　the　initiation　of　plasticity　in　body-centered　cubic　(BCC)　MPEAs.　The　initial　plastic　mechanism　is　embryo　nucleation　assisted　and　the　incipient　behavior　is　strongly　affected　by　LD　and　CSRO.　Specifically,　the　embryo　nucleation　load　Pe　is　reduced　by　LD　and　CSRO　and　the　incipient　drop　P0　is　lowered　by　LDI　that　only　comes　from　atomic　size　difference　and　further　declined　by　CSRO.　This　is　because　LD　and　CSRO　could　boost　embryo　nucleation,　which　can　act　as　precursors　for　dislocation　nucleation.　This　is　consistent　with　the　free-end　nudged　elastic　band　observations.　Although　Pe　is　weakened　by　LDII　generated　by　introducing　extra　elements,　P0　is　intensified　because　severe　LD　could　dominate　the　following　process.　The　dislocation　starvation　mechanism　is　found　in　an　average-atom　(AA)　model.　However,　it　is　replaced　by　dislocation　interactions　due　to　LD　and　CSRO.　Density　functional　theory　(DFT)　calculations　suggest　that　charge　density　distribution　and　the　amount　of　directional　Al-Al　bonding　would　play　a　critical　role　in　the　onset　of　plastic　deformation.　When　a　larger　indenter　radius　was　used　in　MD　simulations,　the　dislocation　starvation　mechanism　is　absent　in　AA　model　due　to　the　reduced　maximum　shear　stress.　Instead,　the　dislocation　propagation　prevails.　With　respect　to　the　orientation　effect,　three　investigated　orientations　demonstrate　a　distinct　yielding　behavior.　©　2023　Elsevier　Ltd