The Chaco War covers the conflict of the same name between Bolivia and Paraquay from 1932-35. A single map depicts the desolate Gran Chaco region, while the 190 counters are split between division-sized units and game markers.
Turns represent one month of time.
The basic unit of the game is the infantry division, with several cavalry divisions thrown in. Both sides receive combat supply and replacements based on how long the supply lines are army HQ to a supply source. A die roll is made and a chart consulted for the result. The supply rules, while not overwhelming, are somewhat more involved than a typical wargame. Thus, bigger forces take increasingly bigger losses.