Welcome to CL basic law today we're gonna talk about Res Judicata. I apologize for talking in Latin but sometimes I have to do it. It’s an old concept in the law but very sound and important it essentially means the court will not allow a party to relitigate the same matter over and over again and when i say matter what i'm saying is the same underlying facts. The court will not allow a party to go back to court and argue diff legal theories based on the same facts in separate suits. You have to bring all your legal theories regarding a particular set of facts in one suit. for example let's say it was a partner dispute over technology development and one partner was accused of stealing tech from another partner and the wronged partner brought the lawsuit and the legal claims he would bring would be breach of partnership agreement, fraud, misrepresentation, theft of trade secrets and fiduciary duty and let’s say they brought all claims except FD and for whatever reason lost and then said well i wanted another bite of the apple i wanna go back to court and argue FD, i think that's really what was the proper claim and go back to court bring another suit maybe in a diff court the defendant can say no you’ve waived that claim/the opportunity to do that you should've raised FD in your first suit because you're asserting the same facts/circumstances but your just pursuing a diff legal theory and under that circumstance the courts would agree with the defendant and bar you from pursuing that claim. When can you raise RJ? you raise it in your answer you raised it as an affirmative defense, something you as a defendant must show. you must show that 1) ther same facts were litigated in a separate lawsuit 2) identify what it is and that they were resolved in that lawsuit and therefore the defendant should be barred from re-asserting them in their present lawsuit. Then you can bring in motion to dismiss the action. you either bring a MOD or a summon to judgment or both- in timing orders, MOD at the beginning of the suit and if you lose that you bring it later at the summoning judgment and then you can assert it at the time of trial. It really is a concept of finality, fairness, and economy. We don't want people constantly going back to court and being a dog with a bone and keep fighting the same thing over and over again. We give you the chance, bring your claims, fight it out, and live with the results. Hope that made sense.