13 rows A bastard sword is too large to use in one hand without special training; I gave one of my guys a bastard sword that's 2d4 onehanded or 3d4 twohanded He enjoyed the versatility and the standardized use of "adding more of the same dice" (plus some loving for those lonely little 1d4s) instead of switching to a different die altogether I'm sure some statistician can tell you how and why this was a bad idea, but we enjoyed it and he kept that sword Thus, a swordsage—that gains proficiency with all martial weapons as a level 1 swordsage—still suffers a −4 nonproficiency penalty with the bastard sword when using a bastard sword onehanded if the swordsage lacks Exotic Weapon Proficiency (bastard sword), but KRyan's correct that there's a gray area ask the DM if a swordsage that picks discipline focus
D D 5e Using Shields With Two Handed Weapons En World Dungeons Dragons Tabletop Roleplaying Games