Design of Emergent and Adaptive Virtual Players in a War RTS Game - Foundations on Natural and Artificial Computation - page 373

2TheGame

Here we describe the basic elements that compose our wRTS game.

Scenario. It will also be called indistinctly region or world and consists of a two-
dimensional non-toroidal heterogeneous hostile and dynamic grid-world. The
world is heterogeneous because the terrain is not uniform, hostile because there
exist a virtual army whose mission is to destroy the human player-controlled
army, and dynamic because the game conditions change depending on the actions
taken by units of both armies. Regarding the heterogeneity of the terrain, each
grid in the region can have one of the three following values: passable (each uni
can traverse this grid), impassable (no unit can traverse it), and semi-impassable
(there is a penalization of 1 point of energy - see below -to traverse it).

Army. There are two armies (also called indistinctly teams, represented by spi-
ders and ladybirds) with a number of units (also called indistinctly soldiers or
agents) and a flag to be defended. One army is controlled by the human player
whereas the other one is guided by some kind of artificial intelligence (AI).
Given a unit u placed in a position ( x u ,y u )inthegrid,its visual range (VR u )
embraces any position ( x, y ) that is placed to a maximum distance φ ,thatis
to say, VR u =

( x u −

. Initially, each agent only
knows the grids that belongs to its visual range. In fact, during the game the
scenario is not completely known for an army and only those regions that were
already visualized by its agents are known. The global information that each
army (independently if this is controlled by the AI or the player) has is the sum
of all the information of their constituent soldiers. Note that (human or virtual)
players only know the rival flag position if this has been detected in a grid by
some of its agents previously. Also, each unit interacts with the environment by
executing a number of actions (see below) and has certain level of health and
energy that decreases with these interactions. The initial values for the health
and energy of each soldier are 100 and 1000 respectively.

{ ( x, y ) | x ) 2 +( y u − y ) 2 ≤ φ }

Fights. Full body combat can be executed at the soldier level by assigning a
random value (in the interval [0,1]) to each unit involved in a fight with a rival
soldier; the energy level of the unit with lowest value decreases 1 unit. A unit
dies when its energy is zero. All the combats between soldiers are executed in
sequence in one turn of the game.

Decision-making. Along the game, the role of players is to make decisions with
respect to the actions that the units of their respective associated armies should
take. More specifically, both the virtual and human player can select a set of
agents and further assign it a specific order that basically consists of a common
action that each unit in this set has to execute.

Actions. The game is executed in turns; every turn, each soldier executes the
last order received by its player. Six actions are possible in this game:
- Move forward enemy: if applied to unit u , then this has to move towards the
closer rival soldier according to VR u , otherwise (i.e., if no rival soldier exists