Actually, the last 3 posts are all actually only partially correct.
file override order is handled differently by file type for one thing and is overwritten by ANY hak in the load order.
anyway this statement is wrong: "Essentially, the load order is (where applicable) 1st, base game assets, the unmodified game (or the game with the community patch), then hakpatch assets, then attached haks, then override folder assets..." As the HAK overrides the override except in one instance, which is graphic file related, where a dds no matter where in the load order, will override a tga, of course two dds or two tga of the same name do follow the corrected load order which is:
Base game assets, the unmodified game (or the game with the community patch), then hakpatch assets, then override folder assets, followed by attached haks, ... IE, hak packs ALWAYS override the override folder, this was done to protect Servers.
As to what content the server sends, it only checks for the existance of a hak, then assumes the content matches. The only file(s) it actually sends to the client are .wok and scripts. So, a client can modify anything in the attached haks, and those will display but no wok meshes are loaded client side, nor are they generated client side as is the normal case, meaning the client never loads a .wok at all, UNLESS it is sent by the server, otherwise, it re-builds the .wok on load of the tile mdl or placeable mdl, it does not read the actual .wok or .pwk file. Try it, you will see what I mean, delete all .wok files from your haks, the tilesets will all still work as designed, using the built-in wok data of each tile .mdl file. UNLESS you are loading it via server, then whatever the server sends the client for the wok will be what is used. Graphics wise, the server mdl will still get overwritten by the client mdl, but the WOK will be protected. Meaning, you can change the local look of any tile that you want, the server doesn't care, but you can't add new doorways etc as the server side WOK file takes priority.
A dds file anywhere it is listed in load order will ALWAYS override a .tga file. Sorry, this is just the way the engine works. So, if your computer can display a .DDS texture, and there is a dds named the same as ANY tga, the DDS will always take priority.
Basically, there is not a simple override order. It all got jumbled up and mixed up when server admins complained about end users/players creating modified local files... The files they truly needed to protect were wok/walkmeshes and any/all scripts which are run directly from the server, NOT the client. Otherwise, client can override the LOOKS of anything, regardless of server side content. So, if a server admin decides that their server will NOT allow adult content, they can do so, yet the clients can use any adult overrides they wish and the display will work for the client. (adult just mentioned to show the limitations and to be more easily understood), so the play can have nude folks running around, yet OTHER players and the server are NOT affected.
as to hak vs override, well the 'override' folder doesn't override anything except local bif content. IE the override will take control of any base/update content but override will NOT take over for ANY hak content that is loaded. IE the hak always wins, again except in dds vs tga relationship.
Also the toolset WILL use 'override' at load time, UNLESS the module also has a .hak with content that is named the same, then the HAK again overrides the override.