So what is this all about? In a play-by-email game, each player submits a set of orders each turn to the game master (generally some kind of automated system) and in turn receives a report of how well (or indeed how badly) they did for that turn.
Atlantis is such a game. The "standard" version is an open-ended game, usually with a couple of hundred players, forming alliances, trading and generally being (for the most part) nice to each other, diplomatic, and not fighting all the time. The game has a general swords and sorcery feel, soldiers are equipped with swords, whilst mages and magic are commonplace.
Conquest is something different. The whole point is to fight and wipe out everyone else. Original conquest started everyone off on an island, with a very much cut down version of the ruleset from standard and required people to build armies, and ships to carry them to the mainland. It featured most of the same rules as standard Atlantis, but no advanced resources and a very basic magic system.
Lacandón Conquest is different again. You still start on an island surrounded by sea (with each player getting precisely the same starting resources), but now the mainland offers the opportunity to find and utilize new resources for the creation of advanced items and a completely redesigned magic system for Lacandón that is unique from all other Atlantis based games.
You will be required to pit your skills against each other player, knowing full well that to
win, you must kill them. Alliances are possible, but there can be only one winner, so watch
your back.