Trees of war is a funny little program (actually it's quite big in terms of lines of code) which shows how trees are in real life basically at war with each other for living space. Thing is, of course, it all happens very slowly by our standards so much so that we can't really notice it except with things like brambles, which grow extremely quickly (even then, I do not recommend sitting down and watching a bramble in the hope of being entertained). Real life trees organise themselves into forests which are sometimes dominated by just one species. This happens because that species is better adapted to surviving there and also because of the numerical advantage they enjoy over any would be invaders. Trees of War speeds up this growing process and allows trees to breed and evolve faster, thus gaining an advantage over the opposition. Even though it all happens quite a bit faster than in real life, it can still take anywhere from 5 minutes to 2 hours for the program to run its course.
The simulation (perhaps a bit of a high foluting word for a low foluting program) tends to pass through four distinct stages: individual, tribal, national, hegemonic. The trees start off alone, the program generating near-equal numbers of each species. Most will die off almost immediately but a few will get lucky and produce some companions. The small groups of trees must evolve quickly in order to maintain their numbers - these tribes of trees do not fare very well when they come into contact with other tribes - they are not yet strong enough to sustain war. Soon though, they will evolve to the point where their numbers are growing as is the amount of land they are covering. Tribes of same species link up, weaker tribes of other species are eliminated through simple strangulation - there is no room for them to grow. At this stage one of the nations may become hegemonic but often the map will end up being divided between two or three. There often follows a period of stalemate as the newly formed nations brush up against each other. Groups of trees sometimes make inroads into the other nations territory only to be surrounded and strangled out of existence. Eventually though a breakthrough in evolution will occur and one side will suddenly (meaning over the course of about five minutes) make progress against the other. Sweeping gains will be made but there is often a 'core' or 'rump' of the strongest trees of the weakened nation left over at this point, which is hard to get rid of. I have even seen counter attacks at this point, as the weakened nation finds it from somewhere to overcome its more numerous rival at a local level. Eventually, though the stronger and more numerous will prevail.
What is remarkable about all this (for me anyway) is that none of the behaviour I have described above has been programmed in. I know this because I did the programming. The trees are exhibiting 'self-organising behaviour' which I am interpreting through metaphors of human behaviour to give it meaning. You may watch Trees of War for a bit and say "Well, I can't see any of that, it just looks like a bunch of trees to me" but to me, this program raises the possibility that some of human behaviour (on a national level, not interpersonal) may be explainable by this self-organising principle. I won't go any further with it than that but if there are any historians out there who can shed any light on the subject I would be extremely interested to hear from you.
The basic rules of trees of war are as follows:
- Each tree lives for two hundred turns.
- For the first hundred turns the tree is growing and cannot spawn.
- The first trees start with a 1.2% (by default) chance of spawning each turn (between 100 and 200 turns old).
- Every turn, each tree tries to spawn.
- If a spawn happens, the tree picks randomly from three of the squares around it (defined by the direction of the wind) for where the spawn will land.
- If the square is water or another tree the spawn is wasted.
- If it is grass a new tree is made.
- When a new tree is made it inherits it parent's spawnchance rating, modified + or - up to 0.1% As trees evolve significantly away from their ancestors they get darker on the mini-map to provide some visual clue as to which species are evolving most rapidly.
- On the titlescreen, the player may change the map size and the chances of spawning which the first trees are created with. A spawnchance of 120 translates into 1.2% in the game.
- Once in the game three tools are at your disposal:
- The magnifying glass changes the view if clicked in the mini-map, or the magnification level if clicked in the big one.
- The pointer also changes the view if clicked in the mini-map or delivers info about trees into the info-box if clicked on one of them.
- The fire tool starts a fire on any tree it is clicked on. Fire spreads onto nearby trees according to the direction of the wind. You may start multiple fires by dragging the fire around.
- The direction of the wind can be controlled by the player by hovering the mouse pointer over the small arrows surrounding the big red one. The big red one indicates the wind direction.