1 ROTV, 1 FOTA, & 1 RTTFF.
If four sets of each are available, the entire battlefield can be built. If not, each battlefield can be built for the round and then disassembled to build the board for the next round.
From J. R. R. Tolkienís Lord of the Rings Trilogy, the fortress of Aglarond sits in the large valley of Helmís Deep. During the War of the Ring, the fortress became the refuge of the Rohirrim, under King Thťoden. Sarumanís armies are now attacking the fortress and have even managed to destroy parts of the wall with an explosion. Even so, it has been said that Helmís deep would never fall while men defended it.
The Heroscape Campaign of Helmís Deep goes through each of major stages from the Battle of the Hornburg. The campaign is split into rounds that take place during these major stages. The rounds end with reinforcement arriving, if the defending army can last that long.