#ossd

First off, keep in mind that in a system, every single alter is their own person/character. They need to be written as different characters, despite being in the same body.

Have at least 4-6 alters. Systems normally do not just consist of 2 people- but they can. This rule is mostly to avoid the "one good, one evil" trope- which can be done well if done properly.

Actually flush out what trauma caused the split in the first place. This trauma originally would be ages 4-9, but other trauma later could have caused more alters to split. The og trauma caused the disorder, later traumas are causing splits/the disorder to react to trauma.

Figure out possible reactions to this trauma (as people react differently to the same trauma, and alters do to)

Break up trauma experienced between them to account for memory differences. This is only if you're writing a system with memory/amnesia barriers, but most people who intend to write a system intend to include this. This means that the "host" very well may not remember the trauma that caused the disorder

if you want to make an alter violent make sure you have a genuine motive for what they are doing, see my post about the killer sterotype

Last but not least: do. actual. research.

Not reading people's statements on tiktok. Not reading people's statements on Tumbler. Actual clinical research. The former can both be helpful for getting the right feeling for what your making, but actual research is NEEDED if you yourself are not a system.