The Double Cross Korriban Quest - Kotor 1
After being admitted into the Sith Academy you'll have a conversation with Yuthura Ban where she asks you to help her double cross her master Uthar Wynn during the final test. This quest has a few twists and turns involved in it with a couple of different outcomes. You'll have the option of telling Uthar Wynn about this if you'd like for +1 Prestige along with some XP and a Datapad that needs to be delivered to Adrenas who can be found in the Sith Academy near the Valley of Dark Lords exit.
Now the possibilities will branch out even more. You have the option of carrying out Uthar Wynn's plan if that is what you want or you can tell Yuthura Ban what Uthar plans to do and open up even more possibilities for yourself. If you decide to tell Yuthura that Uthar plans to poison her -- then she'll give you a passcard that grants you access to his room along with a vial of poison for you to place in his bed.
You also have the option of poisoning both Yuthura and Uthar if you'd like. Either refuse to tell Yuthura how Uthar plans to double cross her or give the datapad from Uthar to Adrenas before you talk with Yuthura a second time. Then you can carry out Yuthura's plan too which will result in both parties being poisoned and weakened during the final fight.
Poisoning Yuthura Ban: After talking with Yuthura Ban the first time return to Uthar and tell him what she is planning. He'll give you a Datapad and tell you to take it to Adrenas who is found at the northern most portion of the Sith Academy just before the door to the Valley of the Dark Lords.
Poisoning Uthar Wynn: Tell Uthar that Yuthura plans to double cross him and then return to Yuthura and tell her that you told Uthar. She'll give you some poison and a passcard to his room which you can then use to poison him.
Poisoning Both Parties: After telling Uthar that Yuthura plans to betray him take the Datapad he gives you to Adrenas in the Sith Academy. Then tell Yuthura that you told Uthar and take her poison vial to Uthar's room so you can poison him. This will result in both parties being significantly weakened during the final battle.