How many polygons should my model have?

[audi]

Every time I try and import my model into Leadwerks it crashes. Any ideas?

[Azure Zero]

The Character model limit is about 60k polys
HD Props should be less than 30k polys

[audi]

I am using Sculptris to create my models. Would to many polygons make the engine lag/Not respond?

[SlipperyBrick]

Yes to many polygons on a model will make the engine unexpectly stop working or even go very very slow. Due to you using Sculptris the one problem with the program is that you have no retopology tools. Retopology is a process where you will wrap you model in polygons the aim is to keep the poly count as low as you can (you can bake normal map information to get a hi res looking model on to a low poly model). I would recommend if you like using Sculptris continue using it but you will need to look at some topology tools. Topogun is very good and very cheap for what it does. In regards to your question though Azure has given you very good guidelines there, whilst nothing is set in stone in regards to poly counts for models there are guidelines you can follow for it :)

[Azure Zero]

If you make something for Leadwerks it needs to be categorised and that will in turn tell you how many polys it should have.

the only things with high count 60k-70k are characters and terrains( not terrain props)
everything else is to be less than 30K, unless you need to give it detail, but you could use texture techniques to give it more detail the is in the base mesh.

And ScrotieFlapWack is correct in that you'll need to define the scuplted model's topology.