The 1704 battle of Blenheim made an interesting game. The supposedly invincible Franco-Bavarian army army of Louis XIV, the Sun King, was located on higher ground with swampy terrain and the Nebel river protecting their front. The town of Blenheim and the Danube River anchored their right while heavy woods guarded their left. The Allies under John Churchill, Duke of Marlborough, and Prince Eugene of Savoy, were faced with crossing these obstacles and attacking uphill with French cavalry waiting.
Marlborough ordered engineers to repair the stone bridge across the Nebel and to assemble mobile pontoon bridges for other crossings. Meanwhile, pioneers with troops assisting, bundled bound branches and threw them into the swamp, across which they laid planks. This work was done after infantry and cavalry first swam across the Nebel to provide cover fire.
To simulate how the Allies dealt with these terrain obstacles, a special unit called an "engineer" was created for the Allied side. These units have the ability to convert swamp, river and damaged bridges to "bridge" terrain. Wherever an engineer unit moves, the computer converts the above mentioned terrain to bridge terrain.
The primary source for information on this battle is the excellent book by Charles Spenser, Blenheim, Battle For Europe (2004). Mr. Spenser is directly related to John, Duke of Marlborough. I am fortunate to have a signed copy of the book.