[KaVir]

In my experience, most mudders already have a favourite mud client which they'd rather stick with. I find it's typically the first-time players who use the simple website-based java clients, and they're not usually willing to pay a registration fee up front. So first and foremost, I'd be looking at how well your free stripped-down version compares against the competition.

Depending on how good your client is, and what sort of plugins the mud owner provides, it could be that some players will later choose to register. But we'd mainly be talking about people who had already chosen to hang around, and just wanted to improve their playing experience. This would still be beneficial to the mud of course, but the biggest stumbling block is the entry barrier for new players, and for that the registered version isn't going to be of much help.

You mentioned that the premium version would have a one-time fee for mud owners "to get the license to run it", but what exactly are they running? A client is normally run on the player's computer - does your client require additional software running on the server? If so, how does this additional software interact with the rest of the mud? Is it a separate application, or does it require patches to be applied to the mud itself? If the latter, how will you deal with the diverse range of different codebases out there? And what happens if people later want to release their mud?

If I'm going to be developing plugins which persuade my players to pay you a registration fee, shouldn't you be paying me, rather than the other way around? I'd be sending you customers, after all - and the harder I worked, the more customers I'd send you!

Or is this intended to be more of a commercial deal, whereby I'm expected to recoup my costs by charging players a small fee to use the client plugins I've written? Perhaps you'd also start seeing independent developers creating and selling plugins as well, if the client become successful.

To be honest, it's hard enough convincing mud owners to add support for well-established mud clients, even when it costs them nothing to do so. Your client would need to offer something truly exceptional to persuade me to invest both time and money into it.