Setting up the game refers to the process that determines who plays the game and with what settings.
The game allows a number of players that can be either human or computer controlled. The players are chosen when the game is set up. A minimal game is just a single human or computer player that explores and conquers a world inhabited by neutral cities only. Players can be invited from Game Center for an online game.
The map size is fixed for various game sizes. Examples:
- 2 players -> 30x30 map
- 3-4 players -> 50x50 map
- 5-8 players -> 100x100 map
- 9-16 players -> 200x200 map
The objective for each player is to grow his or her empire by conquering enemy and neutral cities as well as wiping out enemy armies. The first to rule the world will, well, rule the world. Doh! A player is defeated when all his/her cities and armies are destroyed. A player that has no land armies nor cities but still has air/sea units will still have lost, as he/she can never again conquer another city.
Order of play
The game is turn based and each player performs his or her actions in turn. After all actions are done the turn is ended and the next player gets to do stuff. For info on how the game ends, see the section: Winning.
The map is hex based and normally quite big, allowing for a fair deal of exploration to find it all. The size could be 30x30 or up to, say, 200x200 for large battles. Initially the player sees only his or her starting city and the closest surrounding hexes. The player knows nothing of the map as it is always randomly generated. As the player explores the map more and more is revealed.
The map is randomly generated for each game. For online games the first player generates the map. Generation could be done using a simple "land rising" algorithm until a certain % of the hexes are land. Cities are then sprinkled onto the map randomly. The number of cities depends on the size of the map. After this player capitals are allocated so that no two players start next to each other.
Fog of War
Fog of War (FoW) means that the player does not see everything on the map. First the map itself starts out being covered and then the enemies on the map also covered by FoW. For enemies this means that a friendly unit must be near an enemy for it to be seen. As soon as the own unit moves away from the immediate vicinity of the enemy the whereabouts of that enemy become unknown. A unit marker will be left on the map where the enemy was last seen, but it may or may not be accurate. The marker will not move when the enemy moves away. To actually know whether there really is a unit still in the hex some friendly unit must move close by and take a look. The markers allows the player to not immediately forget about an enemy unit when something happens. If the enemy itself moves out of visual range then no temporary marker will be left on the map.
The map contains a number of cities. Each player starts out in a randomly chosen city. All cities that do not have any player owner will be neutral.
Each city can produce something. The player can select the current production for city and after that it will produce a unit of the chosen type in a certain number of turns. Large units take longer time to produce. If the production is changed then the progress on the previous type of unit is lost. A city that continues producing a new unit of the same type it just completed will get a 20% production time bonus, i.e. the next unit will be faster top build.
Cities can only produce ships if they have a harbor, i.e. are next to a water hex.
When a unit has been produced it will be left in the city where it was completed. The player must move away the unit before a new unit can be produced (no stacking!). The exception here are infantry, armor and air units, these are allowed to stack in a city. Planes will use the city airfield and the other units are considered to be city garrison. The garrison helps defend the city against attackers. Planes are not part of the garrison and will not aid in defending the city when attacked. If a city is conquered then all planes in it are lost, as they are considered to be on the runways. Planes in a city can during the player's turn attack any nearby enemies though.
Neutral cities do not produce anything and do not really act as players at all, they just do nothing. Their cities never have any garrison apart from the one "built in" into a city. Cities of the computer players are not neutral, and they produce units just as human player cities do. Visually neutral cities are gray.
To change what a city currently produces click the city and then click the Production icon. Choose the new production type from the menu. Note that any progress on something else will be lost. If the city is made to produce the same unit type as it was already producing then nothing will be changed and the old production progress is not lost.
Moving garrisoned units
To move a unit that currently is garrisoned in a city click the city and then the Garrison icon. Choose the wanted unit and drag it to move it.
Players produce units in cities he or she has conquered. Each city can produce any type of unit regardless of what any other city is producing. For ship production the city must have ha harbor, i.e. be next to water. More advanced units take longer to produce.
The player selects a unit and can move it around the map. Each unit has a certain number of action points. Each action point allows the unit to either move one hex or perform one attack against an enemy in a neighbor hex. When all action points are used the unit can not do anything with that unit that turn. The next turn all units will have their action points restored to full.
Ships can only move on water, land units only on land. Air units can move anywhere, even over other units, as long as they do not end their turn on top of another unit.
Transport can also carry a certain number of infantry and armor units. To embark onto a transport just move the embarked unit onto the ship. Embarking will consume all action points, i.e. the unit ends its turn when embarking. To disembark a unit select it and move away from the transport. Disembarking is only possible when the transport is next to land.
Carrier ships can carry a certain number of planes and thus work like movable airfields. To land a plane on a carrier just move onto a carrier that has capacity still left. This means that planes can not move over carriers, they will always land on them if moving onto one.
To move a unit click and hold an own unit. Then drag it to a neighbour hex to move it. You can drag it as far as it has action points and one hex costs one action point. When it runs out of action points then it stops following the drag. Moving a unit onto an enemy attacks the enemy and moving it onto a transport or carrier loads the unit onto the other unit if possible.
Air units must always end their turn on an airfield. This means a friendly city or a carrier. If they run out of action points while anywhere else then they are considered to have crashed and are thus lost.
Digging in infantry
Infantry units can be dug in. This gives them a defensive boost. Digging in is an operation that takes 2 turns to complete and while the unit is digging in it will be more vulnerable to attacks. The dig in a unit choose "Dig in" from the unit menu. The status will be shown *somehow*. If the unit is moved the next turn the digging in will be cancelled, but if the unit is left unmoved (and it also does not attack anything) then the digging in will be completed. Dug in units will be visualized somehow. If a dug in unit is moved it loses all the defensive bonuses and must later start over with the digging in.
Transport ships can load infantry and armor units. To load a land unit onto a transport ship just drag it and it will be loaded if the ship has space. To unload an unit the ship should have a special button that shows all loaded units and allow the unit to be dragged out onto the map.
There are three main types of units: land, sea and air based.
- Infantry is the basic unit type. Cheap, slow and weak.
- Armor is a more powerful land units. Faster, more expensive and with more firepower.
- Transports can carry land units. Quite cheap but not suitable for combat.
- Destroyers are fast ships suitable for scouting and light combat.
- Cruisers are powerful ships suitable for combat roles. They can sustain a fair deal of damage.
- Battleships are the heaviest of all the units. They have tremendous firepower and can take a lot of punishment.
- Carriers are mobile airfields that lack offensive weaponry. They can sustain lots of damage though.
- Submarines are sneaky ships that are hard to find as an enemy must be next to it in order to find it. Fragile but can deal a lot of damage.
- Fighters are cheap air units with a moderate range and low firepower.
- Bombers are more expensive than fighters but also have better range and firepower.
Possible extra units
- AWACS planes that have radars that see far. Useful for scouting big areas.
- Land based radar units that are useful for scanning smaller areas.
- Artillery units that can fire from longer distances.
- Missile boat units that can fire from far away.
- Small transports that can carry less units, such as 3 units only.
- Airborne units that can load onto a transport plane and then be unloaded at any time while the plane is flying.
Combat is initiated by moving onto an enemy unit. Each phase of combat costs one action point. Combat means that one of the units will randomly be able to fire and inflict as that unit type does. This means that stronger units will rarely be destroyed with one single attack, but many are required to take it down. Weaker units may be destroyed in one single attack. Each "hit" costs one action point. So for instance if a cruiser attacks a battleship and the cruiser scores a hit the battleship loses 2 hit points and the cruiser can continue attacking or perhaps move away. The battles are thus not fought til death, with the exception of battles between units that have only 1 hit point.
The winner is the player that conquers all cities on the map and keeps them for a number of turns. This allows an opponent that is still strong to retake a city and not lose when he or she still has a viable army. If all enemy units are destroyed and all cities taken then the game ends. If a player loses all units but still has own cities then the game still continues.
There is no score or similar in Imperium, the winner is the one who conquers it all. The game however keeps track of some statistics, such as:
- cities and units when the game ends
- produced units of each type
- lost units of each type
- destroyed units of each type
- total number of destroyed enemy units
- lost cities
- conquered cities
This info is presented when the game ends.
Online games are played through Game Center's turnbased system. This means that the first player creates the game, invites players and plays his/her first turn. After this the game is sent to the next player in turn and he/she can accept or reject the game (normal Game Center turnbased system). All moves that a player does are recorded and sent along with the turn so that the opponent can replay actions and see what happened during other player's turns. Only action that happened near own units is shown.
Some design thoughts about the AI.
- Wolfpack Empire: http://www.wolfpackempire.com/
- Strategic Conquest: http://en.wikipedia.org/wiki/Strategic_Conquest and an example of fog of war: http://en.wikipedia.org/wiki/Image:Sc4.jpg
- Empire: http://en.wikipedia.org/wiki/Empire_(computer_game)
- Discussions about various board games: http://www.boardgamegeek.com/geeklist/86