Here, we present a general multiple RTP design strategy for organic compounds by modulating excitonic coupling between T 1 and T 2 via the degree of conjugation that the linker mediates between donor and acceptor groups. By comparing the photophysics of emitters containing sp 3 and sp 2 linkages (C vs CO), we found that dual phosphorescence relies on how strongly the two triplet excited states communicate. It was demonstrated in two examples that sp 3 C-linked compounds (Cz-C-PTZSO 2 and Cz-C-TRZ) (Figure ), where 9-phenylcarbazole (Cz-Ph) serves as donor and 10-phenyl-10Hphenothiazine-5,5-dioxide (PTZSO 2 ) or 2,4,6-triphenyl-1,3,5-triazine (TRZ) acts as the acceptor (Scheme S1a), could enable dual phosphorescence from two locally triplet excited ( 3 LE) states due to negligible triplet excitonic coupling between donor and acceptor moieties at room temperature (Figure ). In contrast, the sp 2 C-linked counterpart (Cz-CO-PTZSO 2 ) shows only one 3 LE emission at room temperature, together with aggregate phosphorescence in the crystal state, while no RTP was recorded in the other sp 2 C-linked compound (Cz-CO-TRZ).