For the sake of people new to this type of RP, this is a short explination of post order, differnt types of it, and how it generally works.
"What is post order!?" You may ask. In generally, post order is the order of your posting in an RP. The majority of the time, it is considered very rude to break post order, jump into somone elses topic, or to skip someones turn without giving them time to reply.
Let's just start by going into different 'types' of post order.
Structured: Strongly recomended. The basic, and recomended system of post order. Simply put, it is determined beforehand. There's many ways to come up with the order, either by PMing who your RPing with, or doing it in the order that they originally post are the best options. This system is controlled, easy, and funnest to use. As with all other post orders, 2-4 is the recomended number of people. Going over that makes missions drawn out, and boring.
Basic: It's not a free for all, but it can seem like it times. The basic idea behind this is simple. You do not have to make an order or follow it. You can post freely, as long as you do so in a way that lets everyone else have near equal posts as you. Simple as that.
Free-for all: Anybody can post any time they want. Only recommended to experienced posters.
Designed: Not generally recommended. While it's more complicated to set up, a 'designed' post order is just that. Designed to fit to your different members. This means you may make post order RPer 1, RPer 2, RPer 1, RPer2, RPer3, and repeat. You can really make it anything you want. The whole idea is to balance out more active and less active users. While harder to set up, this may be ideal depending on the situation.
Grand: In general, you will see these types of RP only set up by the staff of the site. Grand post orders are set up by the staff for very large missions, and can be used a wide variety of ways. They may involve a post order among multiple topics, or the set-up of multiple topics in one big happening in the wastes. It could also involve the set up of multiple teams, and only allowing one post per team. It greatly varies based on the event, so make sure to pay attention if a grand post order is established. Grand post order is best for very large forum wide events, and should be used only for missions of a grand scale. Best for 6-20 users or NPCs.