Off-grid detailing on/off the campaign

Hello, i’m relatively new to mapping and i wonder how much can be off grid, seeing as though a lot of detail elements in the quake campaign seem to be off-grid i wanted to know if there is a limit, if there is already a thread on this i’ll delete it, Thanks in advance.

Everything should be on grid, but nothing technically has to be.

There are several reasons why you should try and keep on the grid: the main one is that it makes it a lot easier to edit your geometry later down the line (this is also why you should try to stick to larger grid sizes when possible). Your map will also compile slower if you have lots of off-grid geometry, and you might get leaks, or errors with the compiler such as faces not drawing. QBSP is old, so treat it kindly.

The main thing you should avoid is trying to seal your map with brushes that have off-grid vertexes, which frequently causes leaks.