Please see the GNU Project's article on selling free software:
https://www.gnu.org/philosophy/selling.en.htmlAs the Minetest engine is licensed under the LGPL, there is no problem with you selling a game that makes use of the engine, as long as you comply with the license conditions and do not infringe on any trademarks.
The LGPL is a copyleft license, so any software derived from LGPL-licensed code must be published under the LGPL, and source code made available on request (though unlike the GPL, you may link LGPL-licensed code with non-free/proprietary code, if you so wish).
LoseTheGame wrote:Ah sorry Wuzzy, I clearly didn't understand. So what you're saying is that to be safe with selling anything I would need a lawyer? That may not be so easy, but I'll look into it... Thanks for giving good advice about this though.
Selling the software is not an issue. The LGPL simply requires that you make source code available when distributing derivative software.
LoseTheGame wrote:Just to make this more complicated than it already is, what about charging access to a game server? My next projected is going to be a server with my own mods running (and the ones in the default game). If the server was password-protected and I was charging for access, is that still likely to run into issues?
Charging for access to your server is fine. A great many companies sell internet services which rely on free software on the back-end.