Here is your challenge:
Most war-themed games have an objective of either territorial control or capture/destroy (as described earlier). For this challenge, you’ll be pushing beyond these traditional boundaries. You should design a non-digital game that includes the following:
The theme must relate to World War I. The primary objective of players cannot be territorial control, or capture/destroy.
Being short on time, and sort of new to game design, I chose the "easy" option. Here is what I came up with ...
Description: ALLIANCE! depicts (sort of) the situation leading up to WWI where countries formed mutual defense pacts. These were agreements that if one member of the pact were attacked, the other members would declare war on the aggressor. The results was that when war did break out, many countries were immediately embroiled in the conflict.
The basic mechanic of the game is "Match Two"; when players are able to turn up two cards for the same country, that country is added to their alliance. The object is to have the largest alliance when war breaks out (the end of the game). This is written as a game for two players, but could be modified to include more.
My entire game posting can be found on the GDC forums. The game is not complete, but it could be with a bit more work.