Take turns to place one of your own tiles and one of your opponent’s tiles, either in an empty square or beneath already placed tiles to build a tower.
There may only be one tower in a block and its colors must correspond to the colors of the block, i.e. two black tiles in the block allows two black tiles in the tower.
When two blocks grow together, an equal amount of tiles is removed from the two towers, leaving only the strongest tower but potentially with a new controlling color.
The challenge of Lucca is to time the tower building and removal so that your own color prevails in the end.
You control a block by controlling the tower of the block and you control the tower by having the top house of the tower. On a standard 8x8 board, you win if, at the start of your turn, your tower is the highest and has a height of at least 8 houses.
0.7 Tiles removed first from block and then from tower
0.6 1 tile at the time removed from towers and blocks by respective color
0.5 Weaker tower removes houses first (block size tie-breaker)
0.4 No balanced towers, victory conditions at start of turn, tower and opponent houses victory conditions, neutral color may be taken over
0.3 Two actions per turn (one with opponent color), limited tower placement, limited street fighting
0.2 First stable version
0.16 Balanced towers, i.e. not more than one house difference between largest and smallest color
0.15 Place as many of a color in a tower as in the block, losing tower keeps bottom tile
0.14 Tower height new victory condition, limit tower placement to 1 of each color and turn
0.13 Remove as many tiles from winning tower as in losing tower
0.12 As many tower actions as possible of any color per turn
0.11 One block action and as many tower actions as possible per turn, winning and losing tower remove one tile each at the time
0.10 Two actions per turn, 1 block tile and 1 tower tile
0.09 Lost tiles are returned 1 per turn
0.08 Both winning and losing tower loses adjacent tiles in block
0.07 Any number of tiles may be placed in towers, always from bottom, pushing as many of a color as in the block
0.06: Winning tower keeps tiles in block linked to tower, lost tiles are immediately replaced
0.05: Only tiles of own color placed, winning tower loses tiles in block adjacent to losing tiles, block reaching edges new victory condition
0.04: Winning tower loses no tiles in block
0.03: Only tower blocks may expand into each other
0.02 Both winning and losing tower removes tiles in block, number and level of tiles placed in towers linked to number of tiles in block
0.01: Players play with any color either in block or tower, top tile in winning tower and all tiles in losing tower removed, tie breaking rules (tower height, block size, remaining tiles on hand), highest tower at end wins
The complete rules are available in the PDF file to the right. In the following sections, I will describe how they came
One tile in lots - any tiles in towers per turn
The opposite of this rule would be one tile per turn only (since any tiles anywhere would end the game in 1 turn). However, this would not only slow down the game but also make it difficult to build new towers since existing towers would destroy them before they get high.
One color in lots - any colors in towers per turn
Again, the opposite of this rule would be one color per turn (since any colors anywhere could lead to kingmaker situations where one player increases the board presence of another player's color). However, this would remove the whole idea of using other players' colors to further your position, for example by using them to push your own color higher or to push their colors higher to take the first hit in a struggle.
Colors in block
The 1st tower restriction is necessary to create a balance between block expansion and tower extension - you need to do both. This in combination with the "any color in towers" rule rewards player who manages to "swallow" blocks without a tower and use them to extend their own tower
Colors in tower
The 2nd tower restriction is necessary to promote aggressive play. Without this rule, games may stall if players only build blocks and towers in their own colors, waiting for the other players to take each other out.
Towers in block
The 3rd tower restriction is necessary to return some control to the players. You can build up a defence against a block expanding in your direction but not against tower suddenly showing up in your own block.
Winning and losing towers
There are two ways to weaken a winning tower: remove the top tile only or remove the same amount of tiles as the losing tower. Removing only the top tile made strong towers too difficult to defeat but removing the same amount of tiles made the game more dynamic.
There are also two ways to remove a losing tower: remove all tiles or remove all but one tile. Initially, all tiles were removed but with the rule above, this could leave the winning tower with one tile only, i.e. no tower left. It's true that it could be rebuilt immediately but it felt better to let the winning tower stand.
Although not a concept in the game, the thematic reasoning behind removing adjacent tiles of the struggling colors from the block was that the supporters of the two fighting towers would fight themselves in the streets. Mechanically, the rule was important to weaken not only the winning tower (since it would be able to rebuild immediately) but also the block (to prevent the tower from rebuilding immediately). It also adds a tactical dimension where even a lost struggle can be beneficial by breaking a strong block apart and build own towers in the remnants.
It makes thematic sense to reward players who merges two of their blocks. At one point, they were even giving the victory, but since this may happen due to to player mistakes, the reward was reduced to letting the towers merge. Getting such a strong tower is still a good reward without killing the game.
Three block mergers
Given the Tower struggle and merger rules above, why not let more than two blocks merge and resolve them simultaneously. The idea was intriguing but simply too chaotic. What if two towers have the same color? Wouldn't too many tiles of the struggling colors be adjacent, virtually restoring the board. Wouldnt' the resolution just be too complex and bringing the gameflow to a halt? There's probably a reason why similar game mechanisms, like in Tigris & Euphrates, restrict mergers to two blocks.
With the strategic aspects of expanding blocks and extending towers, it was natural to have victory conditions for both. Game tests showed that blocks reaching two edges were to easy to obtain, hence the rule of having to reach all four edges. Game tests also showed that the tower victory height could be connected to the board size (height+width-2), which incidentally is the same as the minimum number of tiles necessary for a block victory.
To prevent endless games between even players, the sudden death end of permanently removing top tiles from tower struggles and stop when a player is out of tiles was introduced. It also added a timing dimension as players must plan to control the highest tower at the exact moment.
... and Rejected Rules
There are of course also ideas that will be rejected and here I will explain why.