In this study, 0.2875 Pb(Mg1/3Nb2/3)O-3-0.2875 Pb(Yb1/2Nb1/2)O-3-0.425 PbTiO3 (0.2875PMN-0.2875PYbN-0.425PT) ternary ceramic composition was doped with 1 mol% MnCO3 in order to induce hard character for potential high-power applications. Dense 0.2875PMN-0.2875PYbN-0.425PT ceramics with 1 mol% MnCO3 addition were fabricated after sintering at 1100 A degrees C. epsilon (r) = 1728, tan delta = 0.35 %, d (33) = 320 pC/N, d (31) = -103 pC/N, Q (m) = 467, k (p) = 0.40, k (31) = 0.24, k (33) = 0.49, and T (c) = 280 A degrees C were measured for Mn-doped ceramics. However, undoped ceramics had epsilon (r) = 2380, tan delta = 1.95 %, d (33) = 433 pC/N, d (31) = -145 pC/N, Q (m) = 60, k (p) = 0.43, k (31) = 0.27, k (33) = 0.48, and T (c) = 285 A degrees C. Acceptor Mn2+/Mn3+ ions presumably substituted B-site ions in the perovskite structure and formed defect dipole pairs. The electrically "hard" character was induced as a result of the domain wall pinning due to the existing defect pairs. Particularly, increasing Q (m) from 60 to 467 and decreasing tan delta from 1.95 to 0.35 % after Mn doping showed that Mn-doped 0.2875PMN-0.2875PYbN-0.425PT ceramics with "hard" character are potential candidates for high-power projector and transducer applications.