road building

Create roads to extent the area of cities and forts and to make movement easy.

Roads removes the penalties of the terrain. Roads can be destroyed by every unit of minimum size 3 and a round of time in the area. The build difficulty of building is road is 4 plus the difficulty of the terrain a city has always a road around them. The building of a bridge costs a point of production.
Two units that build a road together count as one unit with a point more skill.
Taking twice the time in turns to build the road also increases the skill with a point.