Player models need to include a few things in their QC to work right in Garry's Mod.

Files & examples

• https://github.com/robotboy655/gmod-animations/raw/master/gm_playermodel_examples.7z
• https://github.com/robotboy655/gmod-animations/raw/master/gm_anim_includes.7z

Includes

As seen in the example files, your QCs need to include:

• commonbones.qci (male or female)
• ragdoll.qci (male or female)
• hitbox.qci (always male)
• standardikchains.qci

If your player model has helper bones (i.e. for the wrists) present and properly weightmapped, don't forget to add a $proceduralbones line that points to the proper VRD file.

Non-standard player models

It's possible to have a player model that doesn't use the standard ValveBiped.Bip01 set of bones at all, but it will need to have its own animations with the correct activities assigned to what you need. (for a sandbox playermodel, you'd want all activities present, but for a "restricted" gamemode, like Ultimate Chimera, only a small subset need to be present)

You can see a list of activities over at this article.

LOD settings

Very very very important! Don't miss out on these! Read the article about them.