I spent a few minutes looking into it.
OMSPEC_FREQ is set in omdata.h:
[code]// Overmap specials–these are “special encounters,” dungeons, nests, etc.
// This specifies how often and where they may be placed.
// OMSPEC_FREQ determines the length of the side of the square in which each
// overmap special will be placed. At OMSPEC_FREQ 6, the overmap is divided
// into 900 squares; lots of space for interesting stuff!
#define OMSPEC_FREQ 15[/code]
It’s checked here in overmap.cpp, explaining where the 72 comes from:
[code]void overmap_specials::check_consistency()
{
const size_t max_count = ( OMAPX / OMSPEC_FREQ ) * ( OMAPY / OMSPEC_FREQ ) / 2;
const size_t actual_count = std::accumulate( specials.get_all().begin(), specials.get_all().end(), 0,
[]( size_t sum, const overmap_special &elem ) {
return sum + ( elem.flags.count( “UNIQUE” ) == 0 ? std::max( elem.occurrences.min, 0 ) : 1 );
} );
if( actual_count > max_count ) {
debugmsg( "There are too many mandatory overmap specials (%d > %d). Some of them may not be placed.", actual_count, max_count );
}
specials.check();
}[/code]
That’s about all the help I can offer atm, since I’m going to sleep in a bit.