I'm posting this description of the CT rules with the permission of the authors. I had previously sent this to the Daimyo web page, but thought it deserved a wider audience as well.
Note: I will admit from the very first that I have never played Chrysanthemum Throne (CT), though I have played other Chipco rules sets (especially the medieval rules "Days of Knights"). Since I have not played these rules, I will focus on the mechanics of the game and let the reader judge the suitability of the rules for themselves.
Scale and Basing:
The Chipco rules focus on playing the "flavor" of the period rather than simulating every aspect of the battles. For example, there is no set scale for the number of men per stand, and no time or distance scale is given. Therefore, the scenario designer has to use a fair amount of judgment when creating scenarios. The Chipco philosophy is to enjoy the experience with the figures you have rather than worrying about having exactly the right number of figures.
CT, like most of Chipco's rules, is designed to be played on the average size dining room table. For 15mm figures, a table size of 3'x4' should be sufficient for most games, with large battles needing as much as 4'x6'. Stands (for 15mm figures) have a 40mm frontage, but the number of figures is not important. For 25mm figures, distances are doubled, but the players are free to pack as few or as many figures per base as they find appealing. Most stands are 40mm square, though musket and samurai are based on 40mm x 20mm stands to represent the smaller numbers of these "detachments". Leaders, which play a critical role in this game, are based on 20mm wide bases (either 20mm x 20mm for foot or 20mm x 40mm for mounted). Figures based for other games (e.g., DBA) can easily be adapted to CT by tacking down the smaller bases to metal bases to indicate the amount of space taken up by CT units.
Unit and Leader Types:
Unit types are: foot samurai, matchlock men (assumed to include a certain number of bows as well), monks, peasant levies, shinobi (ninjas), and mounted samurai. Foot samurai, matchlock men,
and monks are based on 20mm deep bases and are designated as detachment. These units may attach to one other or to other units (e.g., ashigaru) to add to the base units combat factors.
Leader types are: the taisho (general), daimyo (clan leader), tsukai-ban (general's aides de camp) and champions.
Armies are organized into groups of stands representing the same clan. Stands of 4 or more get a daimyo for free. An army gets (number of clans + 1) of tsukai-ban. Daimyo affect the combat capabilities of units of their clan to which they are attached, as do champions. Tsukai-ban on the other hand are used to help clan groups maneuver.
The game turn is the typical "I go, you go" sequence. The phases are:
1. Resolve matchlock fire.
3. Deploy ambush parties and shinobi
7. Follow up movement
Players of other Chipco games may be surprised at the lack of the "Rally" phase. In most Chipco games, non-lethal damage (usually called "demoralization") is temporary, and can be removed during Rally phase with a successful die roll. In CT, each unit has a set number of damage points which are permanently depleted when a unit suffers adverse combat results. When a unit loses its last damage point, it is eliminated. There is also a "disorganized" state in CT, which prevents a stand from moving in its next movement phase. Damaged units may still charge, but suffer penalties.
Matchlock units may fire at units within 5". Matchlock units attached to other units, e.g., ashigaru, may fire only within their front 45 degree arc. Unattached matchlock units may skirmish and have 360 degree field of fire. Matchlock units may also "snipe" at units hoping to kill attached characters. Sniping is assumed to be carried out by the bows present in the matchlock units.
Firing is a simple die roll cross-referencing the number of units firing at a given target. Results of matchlock fire can be no effect, disordered, disordered and damaged (reduces the unit's damage points by one), or killed. Cover reduces the effectiveness of fire. Foot samurai are counted as in cover (due to their heavier armor), as are units in woods and other built-up terrain.
As with other Chipco games, characters are very important for units to fight effectively. Without an attached character, most units, with the exception of skirmishers, and samurai cavalry can only move forward up to 45 degrees. No facing changes are allowed. (That is, they can move directly forward or "oblique", but can't change face or wheel, etc.)
A daimyo attached to a group will allow a non-engaged clan group to move backwards, but the group is then disordered. An attached daimyo also allows a single unit to rotate. An attached champion will also allow a unit to rotate.
Tsukai-ban (aides de camp) are a bit more complicated. Each clan group starts the game with one tsukai-ban attached, with an additional one attached to the taisho (general). A tsukai-ban can allow a single unit to rotate like a daimyo or he can allow an entire clan group to deploy out of column, change facing or wheel. However, once he causes a unit to execute one of these "complex" manuvers, yet must ride off towards the general. After he departs, the clan group can execute only one additional complex manuver until the tsukai-ban returns (presumably with new orders from the general). So, there is a limit to the number of fancy manuvers that a clan group can execute.
Ambush parties and Shinobi:
Players may secretly designate terrain features with an ambush party (a pair of matchlock detachments with a tsukai-ban) or a party of shinobi. When a player moves his units within range of the feature, the ambush party may attack during the opposing player turn.
Opposing daimyo or champions can issue challenges. During this turn, a unit of that character's clan can be moved backward. Essentially, the character is engaging in personal combat to buy time for the unit to retreat. This is a fairly desparate act which is quite likely to result in the character being killed.
Mounted samurai may disengage from infantry by moving back their full move and becoming disordered.
Once contact is made, units engage in melee. As with DBA, opposing units are lined up so that melee is fought between pairs of units. Unit with attached samurai or matchlock units or with characters get a bonus, as do infantry units adjacent to other "supporting" infantry units. A d10 is rolled for each side and added to the total combat factor. Equal totals result in both sides being damaged. If the totals are unequal, the loser loses 1 damage point. If the loser's total is half that of the victor, he loses 2 damage points and must retreat one base depth.
Follow up and flight:
Victorious mounted samurai must "follow up" when they destroy a unit or cause units to retreat by moving forward to the space occupied by the opposing unit. Infantry may choose to follow up or not. Because infantry gain support for being adjacent to other infantry, this may not be in the infantry unit's interest.
A clan who is reduced to 1/4 of its starting number of units will flee. A percentage (d10x10) will survive the pursuit. The opposing player gets victory points equal to the value (expressed in "koku") of the fleeing units.
The game ends when either the taisho is killed or flees, or the koku value of either side's army has been reduced to 40% of its starting value.