Default specific processes to higher priorities with lutris or otherwise?

Question

I'm running Manjaro XFCE (20.1 at the time of writing) and I would like to make lutris, or some other third-party program, automatically launch all games with a default niceness value of -6 or something of the sorts. I don't want to open the task manager each time a game opens to change the niceness value. I could use a script, but the problem is that negative niceness levels require root, and I don't want to launch games as root for a number of reasons. Is there a deamon that takes care of this automatically or something? It would really come in handy, I do see some drastic performance improvements in some games thanks to this, so it's definitely useful in my case. Thanks.