A Sith does not follow any code in the art of a saber duel. The Sith react on instincts and the guidance of the Force alone with their feelings to guide them. With a reason to fight against the Jedi, a Sith becomes stronger as their will increases to obtain their goal. Find out the KnS reason to fight in the Legend of KnS. This will drives us to be stronger and much better then ever. The better a Sith is at fighting, the more they learn after every duel, win or lose.
The apprenticeship of a Sith is much more unique than a Jedi's. A Sith must only have one apprentice unless it is to be killed by a Jedi. It is known that whoever may defeat the fully trained apprentice, will also defeat the master. A Sith always trains their apprentice to be better than them, so once the master has passed on, the next generation will be stronger. This will create an even better master every time, till the point where the Sith rule over the Jedi. If an apprentice were to be killed, the master is able to take on another apprenticeship to continue his legacy.
