Siege is an attack / defend map. There are 5 capture point wich blu must capture, starting with the capture point on the bottom and working your way up to the top. the general idea of this map is that red (the defending team) has a advantage over blu, by starting higher. Also near the bottom everything is more open, allowing for classes that like space and near the top everything becomes more cramped, allowing for spam classes. each control point, with exeption of the first one, has at least two routes leading to them. the first control point is very close to the blu spawn, and is therefore more easely captured.