Hi people if i use a MD3 format from id my commercial game this will be a legal problem for my commercial game?? and if a do some modification to the MD3 format and call to the new format ".MyFormat" it will be a legal problem?? txs for your help....

It''s legal to use the MD3 format in a commercial product, just can''t use any content from ID Software, for example, textures, models, etc.

As for making a few changes and calling it your own ?
I think this would cause problems as you are claiming it to be your own intellectual property, this is just my opinion though.

as long as you dont use ANY id TOOLS or CONTENT to make your content you can use the file format. changing the format and calling it yours would probably not be the best idea in the world.

though i HIGHLY suggest simply sending id an email and ask them about using the file format so you are 100% sure.