This was originally more of a description of the game than a review, but still informational as it was just released at that time. It was posted on boardgamegeek. I have edited it to reflect more experience and inject more opinion.
I consider Byzantium one of the best designs by Martin Wallace. Wallace has often tried to create confrontational games within limitations, while also retaining historical feel. His three player games often prevent two players from ganging up on the third. This is a difficult trick to pull of and Wallace gets it wrong at times, but definitely not in this case.
The game captures a crucial phase in the history of the Middle East (and the world). It's set around the initial expansion of muslim Arabs in the 630s, taking advantage of the weakening of the Byzantine and Persian empires after decades of war to the death. Players have the opportunity to shift their efforts between the Byzantine and Arab armies. Victory is most likely when these two sides remain balanced.
The board and pieces
The map includes present day Greece, Turkey, Iraq, Saudi Arabia and Egypt, Cyprus and Crete (and areas in between). Byzantium reigns over the Mediterranean coast and Syria, the Arabs in Arabia and the Persian empire lies prostrate for its enemies to attack.
The board is nodal, ie represents the main cities, connected by roads. The three cities in Arabia can not be reached by Byzantine armies. There are several sea routes, to and from Crete and Cyprus.
The playing pieces represent armies, each player having a Byzantine and an Arabian army. Furthermore there are cylinders on every city, showing the level of population. There's also a number of cylinders in player colours, to show fortifications. The player maximum is 4.
There's also a set of orange blocks that constitute the Bulgars, who can descend upon Greece and Constantinople by player action.
Each player has his personal board showing areas for Byzantine elite units, normal units, city levies and logistics, and a treasury, the same for the Arabs. Since a player has only one playing piece for Arabs or Byzantines, the elite and normal units make up your field army. The city levies can be used to defend any town of that side. The logistics determine the movement of the field army. Smaller blocks are put on the board to indicate the size of the armies and logistics points. There is also an active action blocks pool, which can be used for placement on the main board. The treasuries can be used to buy new blocks.
The game board and pieces are all well up to standard.
The essential features of the game are that each player can use both his Arab and his Byzantine army during a turn, and the use of the smaller blocks to perform actions. The former makes for a dynamic game, where players manoeuvre to defend their own cities and threaten those of others. Also the players have two score tracks for their Arabs and Byzantines. If the score on one track is twice as high as the other at the end of the game, the lower score doesn't count.
The latter mechanic puts a limit on the activities of the players. Turn length is not set, but determined by three players passing. If players have lots of blocks in the logistics areas and in the pool, the turn can take long. If players build large armies, turns will be short. There are three turns in the game.
The game is therefore about balancing: between Byzantines and Arabs and between the size of your armies and their activity. This feature works very well.
Players score victory points during the turns by capturing or taking control of cities, by building mosques or churches or at the end of the game by the number of city cylinders they control.
Players take actions in clockwise order. There are a many different actions a player can take.
- Take control of an uncontroled city. This is done by placing a small block of your colour from your active pool on the city stack. This mostly happens early in the game.
- move an army. This costs one block from your logistics area from one city to another, but three for a distance of two cities and six blocks for another step. Moving across water costs double, and even double that if another player blocks you by controling the opposite navy (ie the Byzantine navy blocks Arab armies and vice versa). Upon arrival at a city the player may attack it.
- activate the Bulgars. This is done by placing a block on an orange square on the main board. This strengthens the Bulgar units by two and allows them to attack. Initially this is at two points in Greece, but if successful the Bulgars could roam freely.
- build a fortification. This is done by placing a block on the appropriate square on the main board. Players have two cylinders to place on cities. These cities now have increased defense. Points scored by the Bulgars are added to the Arab score track.
- add one cylinder to a city. This is done by placing a block on the appropriate square on the main board. Three Arab and two Byzantine cylinders can be placed per turn. Cities have a maximum of three cylinders (or four if they have a fortification).
- control the Byzantine Emperor or the Arab Caliph. This is done by placing a block on the appropriate square on the main board. This immediately give you two VP on the appropriate track and a free elite unit for that army for the rest of the turn.
- control the Byzantine or Arab navy. This is done by placing a block on the appropriate square on the main board. This increases the costs of moving by sea for the opposite armies.
- attack a friendly city. This is done by placing a block on the appropriate square on the main board. It is normally forbidden for Arab armies to attack Arab cities, and likewise for the Byzantines. However, by taking this action, that restriction is lifted. One Byzantine and two Arab cities can be betrayed by their own each turn.
-Build a church or a mosque. This is done by placing a block on the appropriate square on the main board AND paying 6 gold from the appropriate treasure. This generates two VP on the corresponding VP track. Unlimited.
- Tax. Place any number of blocks from the active pool and receive 2 gold per block in the treasure of your choice. This is of course a way out when you are strapped for money, and can also be used to shift gold from one treasure to another, although not very efficiently.
- Buy new blocks. New blocks can be bought for three gold each. Arab gold can only be spent on Arab armies and logistics.
You can place up to three blocks per action from your pool to other spots on your own board. Also you can buy a maximum of three blocks per action. While you can put blocks with both Byzantines and Arabs from your pool in one action, buying blocks can only be done from one treasury.
Combat is fairly simple. Sixes on a dice are hits and the largest army remaining at the end of one round of combat wins, ignoring the casualties. This benefits larger armies, although they are not necessarily more effective (see below). A losing army retreats.
Attacking an army
When you move to a city defended by an army, it may retreat. If it doesn't both armies roll the following number of dice: one for each normal unit up to three, and one for each elite unit (no maximum). This gives an advantage to elite units, but they are more expensive in maintenance.
A defending army may always retreat before battle.
Attacking a city
When a player attacks an undefended city, the player controling the city may allocate levies for its defence if available. This is resolved like normal combat. Although the levies are unlikely to win, they may wear the attacker down. If the levies are dealt with the defending player rolls one dice for each cylinder in town (including the fortification). If this results in the attacking army ending up smaller than the city, the attacker retreats, otherwise the town loses one cylinder and forticifation and the attacker gains one VP and one gold (in the appropriate treasure) per remaining cylinder.
Constantinople is a special case. It cannot be control by a player and when attacked it rolls five dice and each six results in two casualties. This is potentially deadly as the Bulgars found out in one game. After eight casulaties they were effectively out of the game.
The game immediately ends if Constantinople is captured by the Bulgars or the Arabs. In that case only the Arab points are scored. Five extra points are scored for capturing Constantinople.
This is a possible kingmaker action. Any player within 5 points of the highest Arab score can propel to win by activating the Bulgars and capturing the capital. However, it is difficult even with all 11 Bulgar blocks on the board. Other players may choose to use the Bulgars on other ventures to make sure they don't attack Constantinople, or try to weaken the army by attacking it (or attacking other well defended towns).
When an army retreats, it must end in a friendly city (ie. an Arab army in an Arab city). If it can not in one step, it must move through enemy cities and lose one block from the army per enemy city passd through.
End of turn
Actions thus continue until three players have passed. The first player to pass is starting player for the next turn, which is a benefit, because you can then pick useful actions as controling the Emperor of the Caliph.
At the end of the turn all your blocks from the main board (apart from those marking control of cities) return to your active pool. Half of the blocks lost in combat or other ways (rounded down) return to your active pool. Also, the players receive two gold for each cylinder. The income from Byzantine cities goes to the Byzantine treasury. Then the armies are paid from the treasury. Normal units cost one, elite three and levies two per block. If the army can't be paid, blocks must be removed to fit.
End of game
At the end of the third turn two additional points are scored per city cylinder (not the fortifications). The two tracks are then summed, provided neither is twice as high as the other. Highest score is the winner. In the case of ties, the largest number of cities under control decides the winner.
The feel is quite different from earlier Martin Wallace games, although it continues the indirect approach: players do not identify closely with any party in the conflict, like in PotR, where players are not the Italian cities, but condottierre that hire themselves out to the cities.
To me the game is challenging and highly enjoyable and I think it has the same range of strategies as Princes of the Renaissance or Struggle of Empires. It seems that the mechanisms drive players towards a balancing act between the warring sides and building up armies or keeping them mobile.
Two notes on strategy
About positioning your armies. In the best case you use your armies to corner part of the board. But at least make sure that you are not putting yourself in a spot where you are blocked by other armies and towns you cannot attack.
Building Churches or mosques. At two blocks and 6 money from your treasury for 2 VP, they are not very expensive. For context, for 6 money you have two blocks, so it effectively costs you 4 blocks. How many points can you score with four blocks in alternative use? Probably less. The only advantage of using them as army or action blocks is that you not only score points, but also take them away from others.