Here are some rules off the top of my head for a Phylo strategy game. These rules are somewhat complex and not for young children. The rules were written in a somewhat stream of consciousness fashion so forgive if they're difficult to understand. Please feel free to ask questions. I have this idea in my mind and I simply can't be sure if I translated to writing as well as I would have liked. More important than the specifics is the general feel of the game and the sorts of themes that I'm going for.
Phylo Strategy Game
This game is played on a board divided into many squares. Each square has footprint limit which represents the fertility of the land and restricts the amount and size of plants that can grow there. The board will also have various features such as lakes, rivers, volcanoes, etc.
Description of Card Features
Evolution Points are the currency of the game and can be used to play new cards, activate card abilities, and pay for support costs. EP represent the ability of a creature to support other forms of life. Most basic creatures (such as plants and small animals) will produce EP while more advanced animals most likely will not.
Each turn many animals will require a certain amount of support paid for with EP to keep them from dying off. Smaller animals will therefore have a net production of EP while larger animals will have a net consumption of EP. Most plants do not require any support.
Each plant has a footprint which describes how many resources that plant needs to support itself. Cactuses and lichen for example will have a very low footprint while large deciduous trees will have a much higher footprint. Plants with higher footprints generally provide more EP.
All animals are given a size. These sizes are tiny (insects, worms), very small (mice, frogs), small (cats, snakes), medium (wolves, eagles), large (lions, horses), huge (elephants, giraffes). This size is used to determine when an animal can be consumed as prey by another animal. For example, a hyena which is a medium sized animal may be able to eat large and smaller animals.
All animal cards have an attack rating. This is a number ranging from zero to six which represents how effective that animal is at killing its prey (whether plants or animals). Most animals will have an attack rating of around two while more ferocious animals or venomous animals will have higher attack ratings.
At the beginning of each round, a card is drawn from the environment deck. This deck represents the changing environment that every animal and plant must deal with. When a card is drawn, its affect takes effect immediately and that effect remains in play until the beginning of the next round when another environment card is drawn. The effects are always global in nature and can be either bonuses or penalties. A bonus may increase the EP generated by certain cards while a penalty may be a natural disaster such as a flood.
Player turns are taken in order.
The player draws a card at the beginning of their turn and places it into their hand. The player then accumulates their EP from all their cards and distributes it among their other cards to pay support costs. The player may choose not to support a card at which point it dies off and is removed from the board. With the remaining EP the player may play cards from his hand or activate card abilities. A player’s EP remains in play until the beginning of their next at which point any unused EP is lost.
After this general phase, animals can move up to their movement limit. Most animals have a movement limit of one but some (birds especially) can move two or even three spaces.
After this movement phase, is another general phase where cards can be played and abilities can be activated.
Abilities can be activated at any point during opponents’ turns.
Each player begins the game with a grass plant card (or equivalent) in one of their starting areas.
Plant cards are played by paying their footprint value in EP. Plant cards may be played on any square where that player already has another animal or plant card as long as the footprint limit of the square is not exceeded by all plants in that square. Plants can even played into squares that have opponents’ cards in them as long the player has a card of their own on that square. A player may remove his own plants from the board at any time during his turn.
Animal cards are played by paying their support cost in EP. Animal cards may only be played onto squares that already have a card that the player owns on them. Animal cards may not be moved the round they come into play.
Many cards have passive abilities such as thorns or poison. These abilities give them special exceptions to certain rules. For example, thorns or poison would make the animal or plant inedible. These abilities are always active.
These abilities are inactive until they are activated by the player. Activation almost always requires a cost in EP and can only be used once per round. These abilities could include a skunk’s spray ability which allows it to not be eaten by a predator when activated.
Many animals can eat other animals and plants. This ability can be activated once per turn at no cost. The animal must be on the same square as the target creature. A six-sided die is rolled and if the number rolled is equal to or lower than the predator’s attack rating then the target creature is removed from the board.
Playing Evolution Cards
Evolutions are cards that can be played using EP on the player’s own creatures. These cards remain on the target creature permanently and can drastically modify its abilities. Evolutions can include small things like lowering an animal’s support cost or drastic things like altering an animal’s size and all the ability modifications that may entail. Multiple evolutions can be played on the same target and their effects stack.
Playing Effect Cards
Effects can be played using EP at any time. Their effects take place instantly and wear off at the beginning of the next round. Effects may target specific creatures, players, or everyone. Large effects can be very expensive but also very powerful.
Humans are a special animal card. They are subject to all the same rules as other animal cards but they have the ability to build a village and are therefore necessary to win the game. Humans require a huge amount of support to maintain which means the player must plan carefully to build all the proper support before bringing humans into play. Each turn the player can activate an ability on the human to build a building in the player’s village. If the player has no humans in play then their village is destroyed back to zero buildings.
Winning the Game
The player that wins is the first player to finish their village (build 10 buildings). Doing this will require at least one human creature in play but multiples can greatly expedite the process. Due to their high support amount as well as the high cost of actually constructing a building the player must carefully manage the rest of their base to ensure that they can support continued development of the village and prevent other players from killing their humans.
Flow of the Game
The player begins the game with a very small plant and he must slowly use the EP generated from these low yield plants to play progressively more complex plants. More complex plants will not only have better abilities but they will also yield larger amounts of EP relative to their footprint size.
It won’t be long before the player will want to expand and he will need to do this by playing animals. Animals can move to unclaimed squares and allow the player gain a permanent foothold there by playing plants next turn.
Similar to plants, animals will start small due to limited EP production. As the player broadens his biological base and begins to accumulate more EP each turn, he will be able to play and support larger and more complex animals all the way up to humans.
The squares on the map will vary considerably in their footprint limit. Fertile squares will boast very large footprint limits that can support huge amounts of plants which in turn yield significant EP. These squares will unsurprisingly be heavily contested.
The player will have to maintain a careful balance between conflict and maintaining a strong base of support. A few large predators can easily drain a player’s excess EP due to their high support costs, stunting the player’s ability to expand and adapt elsewhere. Humans require so much EP to support and to construct buildings that it is difficult for a player to maintain large mammals and humans in play at the same time. Humans are very strong hunters (attack rating of five) and are therefore very capable of conducting a strong offensive against other players but they cannot hunt and build in the same turn.
General Plant Groups and Guidelines
Grasses require a very small footprint to grow and are therefore very cheap. This makes them hardy in the sense that other players will generally target larger plants for removal first but they also produce very little EP.
Generally the next step up from grasses, shrubs still take a relatively small footprint but they also yield more EP.
Flowers have a slightly larger footprint than grasses but less than shrubs. They also produce little EP. Unlike other plants, flowers usually have the ability to move. This movement is generally granted through an activated ability and in some cases it may be required to move with a small or tiny sized animal.
Trees have the largest footprint but also provide significantly larger amounts of EP for their footprint size. Trees can range from the low yield coniferous to very high yield fruit bearing trees.
These plants have relatively low footprints and low EP yield but they generally boast unique abilities. Fly traps have the ability to eat tiny sized animals. Kudzu can progressively expand its own footprint and kill off other plants in the same square as a result.
Fungi have small footprints and lower EP yields but they generally increase the footprint limit of the square they are on. This can give them a lower, neutral, or even negative effective footprint. The fact that they have a footprint forces them to be placed in a square that can already support other plant life.
General Animal Groups and Guidelines
Tiny animals are generally insects and other small bugs. These animals have a very low support cost and provide some EP. Many insects have interesting abilities even if they aren’t very powerful in an absolute sense. Their cheap nature allows many of them to be in play at once and a swarm of insects can be at least as devastating as larger animals if other players aren’t careful.
Very Small Animals
Very Small Animals are fairly cheap but provide a large EP yield relative to their support cost. This makes them good at providing a base of support for larger animals.
Similar to very small animals, these animals yield large amounts of EP relative to their support cost. The large majority of a player’s EP will come from plants, very small animals, and small animals.
Medium Animals when taken as a whole will provide slightly more EP than their support but the support cost and EP yield of individual animals will vary drastically.
Large Animals yield little or no EP and generally have high support costs. There will be relatively of these animals in play at any time due to their high support but they can have a very perceptible impact on the game. Humans are large animals.
There are only very few huge animals and similar to the large animals they yield little or no EP and have very high support costs. Their main advantage is that very few animals can hunt them allowing the player to have a virtually uncontested presence on the map.
I hope the themes that I'm going for are pretty self-evident. I want to try to recreate the biological pyramid and show that you need tons of small animals and plants to support big animals. I especially want to show that humans need the most support of all and they need all the other animals and plants. I want to show the sort of natural selection that takes place where animals can wipe out other animals that aren't protected against them and show that animals survive and grow based on this predator/prey equilibrium. I want to show the role of evolution in allowing animals to live with each other and their changing environment.
The game should be highly competitive but it still downplays needless aggression because the ultimate victory is not gained by wiping out the other player. Aggressive play is necessary for victory, however, as players fight over limited resources. Most importantly the game should emphasize exploring different strategies toward victory and adapting your own tactics on the fly based on the other players' strategy.