Art. 1031 Incidental demands allowed

If you're already involved in a lawsuit, you can bring related claims into that same case instead of starting a brand new one. These are called incidental demands. You can file one against the person who sued you, against someone else who is also a party in the case on your side or the other side, or even against a person who isn't part of the case yet but should be.

There are four types of these related claims. A reconvention is when the person being sued turns around and sues the person who sued them, within the same case. A cross-claim is when one party sues another party who is on the same side of the case, like one co-defendant suing another co-defendant. An intervention is when someone who isn't already part of the lawsuit asks to join in because they have a stake in the outcome. And a third-party demand is when someone already in the case brings in a new person who isn't part of the lawsuit yet, usually because that new person might be responsible for some or all of the problem.

The point of this rule is to let courts handle related disputes together instead of forcing people to file separate lawsuits. This saves time and money, and it keeps everyone with a stake in the situation in front of the same judge at the same time.