Tuesday, January 30, 2024

Skyship Battle

I was exceedingly elated when I discovered a blog article Xaoseed wrote in 2021 about the game mechanics I posted back around that time. I didn't spot it until yesterday. He (she, they) playtested them and found that they worked as I'd intended. So, thanks awfully for that! I wanted mechanics enabling fairly detailed movement rules involving the speed and direction of winds while merging ship battles with traditional OSR player-character and monster combat. So: mission accomplished. With Xaoseed's permission, I'm reposting his article here, for the record!

21 August 2021

Actual Test: Calidar (Fantasy Space Combat Rules)

tl;dr: fantasy flying ship combat where the wind direction matters - surprisingly easy to pick up, lots of fun and some great old school damage tables detail that makes ship combat more than just slugging away at hull points.

After testing two magazine-published sets of rules for fighting magical flying ships - the 3e adaptation Shadow of the Spider Moon and the 5e Aces High aerial combat rules from Arcadia #3 published by MCDM as well as the original AD&D Spelljammer we come to the thing that kicked all this off - Calidar.

The Calidar supplements come from Bruce Heard, creator of the magnificent Voyages of the Princess Ark, one of the original D&D Flying Ships (*the* original?), as a vehicle for him to continue with flying fantasy ships as Princess Ark is no longer continuing. I grabbed the Calidar books because I love me my flying ships and also pulled down the skyship combat rules from his blog. Initially, the ruleset looks scary as hell but I cobbled together a word doc and sat in the pub and red-penned it until I figured out how it worked then took it to the table.

Mimicking the 'big vs fast' set up of previous fights I set up the feature ship of the setting - the Star Phoenix - against a fast ship, the Lucky Deuce. We put down a hex grid and ran the same altitude and edge-of-board escape conditions for the 'heavy' as before. The first really interesting thing about the Calidar system is that ship speed is wind-driven - the sails matter - and first thing to do is dice up the wind. We got a strong wind, just short of a damaging gale, blowing straight down the board. One of the hardest pieces of the system for me to grok initially was the points of sail until I finally got that the wind directions were split more finely than hexes have sides and suddenly it all made sense.

The second interesting thing is that initiative is diced per round for combat actions but movement is done in order of speed - and big ships can put on more sail and go faster. We were surprised to find that the Star Phoenix was faster than the Lucky Deuce (though harder to turn). We set off, everyone out of range to start then after movement where both gained altitude, the first long distance fire was exchanged. The Deuce landed shots to the hull and the Phoenix fired back and swept away almost a quarter of the Deuce's crew. Here another interesting system point came up where each hit led to a roll on a table to see what was hit - masts, crew, weapons or the hull. This was a very interesting aspect of the system, making it harder to knock out an enemy ship but inflicting lots of other pain on them.

Round 2 - we diced to see if the wind changed - as there was no DM we adapted the system by rolling 2d8 to get under the count of turns since the last shift in wind. The wind stayed stable for now. The Deuce fired, scored another hull hit and both ships soared onwards, with the Deuce using its superior maneuverability to stay out of the Phoenix's broadside fire arcs.

Round 3 - we diced and there was a chance for wind to change but testing for change in strength and change in direction led individually to nothing - a flutter but no actual change. The Deuce took advantage of their positioning to fire again, landing a ballista bolt and managing to knock out the starboard forward ballista on the Phoenix. Then both ships moved: the Phoenix diving and the Deuce keeping pace and lurking ahead of it.

Round 4 - a pattern was setting in with the Deuce peppering the Phoenix bows with mid range fire. The port forward ballista was knocked out this round, then after both had moved two shots threatened the Phoenix masts but failed to cause telling damage.

Round 5 - another round of fire and the Deuce knocks the Phoenix below 70% of hull points, worsening their maneuverability a grade and causing it to sink an altitude level per round - now they have to advance 2 hexes before they can turn one face, leaving the Deuce weaving circles within the Phoenix turning arc as it tried to bring its broadside weapons to bear. The chance to climb out of the gravity well and escape into the Great Vault was also closed, only one path to escape remaining - the board edge.

Round 6 - the Deuce fires and knocks out a starboard aft mast on the Phoenix.

Round 7 & 8 - the wind changes, slowing, and the dance continues at lower speed. The Deuce throws ballista and scorpion bolts at the Phoenix, shaving off hull points down to 50% of its original total.

Round 9 - the Phoenix captain finally figures out their tactics and races away across the grid before turning slightly at the end and leaving their broadside arc facing down the line the Deuce needs to approach (or if the Deuce turns wholly away it would allow the Phoenix to flee). Alas the damage to the Phoenix ballistae is telling and only the aft set remains to fire as the Deuce stays out of range of the Phoenix broadside catapults. Too close, and the Deuce weaves out of arc, too far and the catapults are out of range - the captain of the Phoenix is growing increasingly nervous about surviving.

Round 10 - the Deuce sails up and misses most of their scorpion shots while the Phoenix fires back with their lone ballista and flees for the board edge. The Deuce follows, allowing their own ballista to get to optimal range before firing and landing decisive hull hits. The Phoenix is looking shaky but is only one turn from the board edge.

Round 11 - knowing this is their last chance to stop the Phoenix, the Deuce fires everything, no matter the range and misses entirely. Heartened by this last spot of luck, the Phoenix flees off the board edge, with a shattered mast and two destroyed ballista.
A Hammership and Wasp paper mini standing in for the Star Phoenix and Lucky Deuce respectively

Overall the system was a lot easier to use than it appeared from the heft of the assembled rules. The points of wind took a little getting used to but once that was done, the challenge of turn limitations due to maneuverability class, fire arcs of the ships and the potential to shed or gain movement points as ships adjusted heading was a great fun part of it that really made the Calidar rules feel distinctly different to the 'powered flight' of the other systems tested.

The ships feel complex but not too complicated - initially I thought the 'roll on the damage table' for every hit to be preposterously fiddly but it quickly became easy to handle. The consequences of exceeding damage thresholds in certain categories was potentially very interesting - a lucky first shot by the Phoenix killed 8 out of 39 crew. Another similar strike to the crew would have been guaranteed at minimum to knock it below 3/4 of the crew, making all shots 10% harder to hit and that would have made life much easier for the Phoenix. On the other hand the Phoenix has nine masts and happily risked strikes to those as it would have taken at least 3 lost to impact maneuverability and each of those strikes was damage diverted away from the hull.

Another very interesting aspect of the system that I liked a lot was the 40 second round - if heroes had been present, acting individually, they could have gotten in 4 actions per ship combat round. This is also reflected in the relatively high rate of fire of the weapon systems - twice a round in most cases. Chucking fistfuls of dice about - however justified by the system - is a lot more fun than examples such as original Spelljammer with 1 in 3 rounds or 1 in 4 rounds firing rates.

The crews did not get to play a great part in this fight but could have. The boarding mechanics are very interesting with a compare ratios then roll table. I used it to stage out a guards raid on a safe-house in my home game and it is a nice neat system for that. We checked what might have happened had the Phoenix gotten to grips with the Deuce - the boarding party from the Phoenix would have been repulsed at a high cost to the Deuce, which would have left the Phoenix free to either sail off happy that they would be unlikely to hit them as they left or board again with even more chance at success.

Some really nice pieces of this system are:
1. How wind and facing matters along with relative speed and altitude change.
2. The 4-to-1 hero-to-ship action tempo is a nice way to keep the pace of ship activity high while also allowing heroes to make a real difference.
3. This was ship-on-ship but there is a large roster of monsters and clearly a lot of thought gone into integrating monsters as ship opponents. Taking a big dragon up against a ship could be a lot of fun.

If you read through all the posts as presented on the blog it is not easy to make sense of the system but assembled together and read through together (as in its intended published form) it makes a lot more sense. There is guidance on how to calibrate it to the system of your choice with multiple proposed approaches suggested from percentile to adapting d20.

My only complaint is that as the system is currently posted in parts, it is missing the editors run through of elaborating on terms the first time we run into them - it took me a while to find SR meant Structure rating, what windward meant and so on. There are some good worked examples in among the text to help it all make sense. I think the combat round sequence should be right up the front to help frame why all the individual pieces of the rules are important and where they come into play.

Certainly I would be happy to grab this when it eventually gets released. It has some real old-school flavour in the look up tables but I was surprised how universal a rule set it turned out to be. You just need to select the correct damage scale and then decide whether you want to use percentile or d20 to hit and off you go.