I’m working on a project that plans to use unreal 4, and is in its very early stages. I was wondering what a good polygon count would be for characters. Its an FPS with a combat system that will take you up close and personal with almost all of the characters. Target specs are mid-high range. Thank you for your help.
Polycounts is a rather subjective subject as the problem of pushing polygons through hardware rendering was solved long a go.
Example I did way back using a 8800GTX 512
Hardware Test with a 750K Player Model - YouTube
The only guideline I can recommend is to use what you need to define shape and form and lots of LOD models. In other words if it needs to be round make it round and not something that looks like it was hit by a hammer or looks like Kryten. On the other hand your player model does not reallllyyyy need five toes. 
The flip side is it’s generally the texture fill that can effect the overall performance but so far I’ve found the UE4 does a lot of the optimization for you and more so if using instancing.
As for a number I would say about 50k boarders on excessive for all elements of the player model, including weapon. (aka my opinion)
But as a tip at no additional cost I generally go high at the start as I found it much easier to make less out of too much than it is to add when the design calls for more and then just see what happens.