hehe not easy questions
well, basically build script is optimized to build in the native git env, when you are downloading megaglest-source-3.12.0.tar.xz (designed for ~distro maintainers) then at the same time you are choosing "the hardest way" 
and ~ you should do compilation by hand "cmake <a lot of parameters which fits to your preferences> ... ; make"
I build the package from the source directory, but how to install it to $HOME/local/games ?
heh even much harder question because e.g. it depends what you want to get on the end and what methods are acceptable for you 
in general my personal preferences for such private build are related with sequence "cmake <a lot of parameters which fits to your preferences> ... ; make; cpack; 'install'" but this is not related with $HOME area
First, let me paste something from #megaglest
<andy_5995> As far as installing from a build, perhaps I should have been more clear -
<andy_5995> I am used to using ./configure --prefix=$HOME and then running make install
<andy_5995> I don't know how to do that when building mg
<titi_linux> well its not like that
<titi_linux> look at other (big) games, they all cannot be build so easy
<andy_5995> hmmm.. I noticed that actually, the very first time, right before I met you
<andy_5995> I was very surprised at how easily it built
<andy_5995> I thought I was stuck with 3.9 from the Debian repo. But I figured what the hell and downloaded the source and it actually built!
<titi_linux> send those kind words to softcoder and filux, they made most of this build process
What I often do with source packages that include a configure script is ./configure --prefix=$HOME or $HOME/local or some such thing. Sometimes I will install as root ./configure --prefix=/usr --sysconfdir=/etc
I don't have an extensive background in coding, or git, but I believe I understand enough of what filux and softcoder said to accept their answer.
The installer package worked fine for me today, and I'm sure I will be quite happy with it.
Now the geek in me still must ask:
Isn't there a file I can edit (and I do have experience editing source code and Makefiles), that I can hard-code a path that I'd like the game installed to? So the built binaries know where to look for everything?
But perhaps it's not even really an issue if you're using relative paths. After I build, I could just copy what I need to $HOME/local/megaglest-current (for example)?
And then I'd extract the data to the appropriate directories. Simple.
I know there may be a little communication barrier here, and I'm often not the best writer, so please forgive me if I'm not being clear.
I will end, or summarize by trying to make my point better. I am fine with everything, but I am mostly curious.
Also, I was a Slackware user for many years, so am just used to, or familiar with, building from source and then installing (thought I used Slackbuilds a lot which made things very easy).
But everything is working well, and I don't wish for anyone to spend a lot of time trying to answer my questions further. Thank you!
Perhaps I should add, for some reason I don't really know, I think running software built on my own system is better than running software built on another system. maybe that is because I "grew up" with Slackware (my first Linux distro). To be honest, I don't have the knowledge in this area. Perhaps that should have been my first question: Is there much advantage to running software built on one's own system, instead of running software that's been precompiled?
