Are there any rule or gameplay changes in Conquests?
There were some minor rule changes and gameplay tweaks introduced in Conquests. Here is a brief overview of them, but for more, see this thread: defensive bombard (if a unit, like an archer, has this, it will attempt to take off one hit point from the attacking unit, like a bombard unit), lethal land and sea bombard (air units like bombers can now totally kill units in an air strike), craters (if a bombard attack is successful in destroying everyone on that tile, a crater will appear, and it has to be cleared before it can be worked), barricades (an upgraded fortress, built on a tile, and it provides 100% bonus to defense as well as uses up all of a unit’s movement points), two new terrain types (marsh (just 1 food) and volcano (just 3 production, and you can’t improve it), four new resources (tobacco, sugar, oasis, tropical fruit – all bonus resources), bonus technologies (Philosphy now grants a free technology if researched first), and more. See the mentioned thread for more rule cha