Monday, February 28, 2011

Sea Hexes

Okay, I've confessed my brain doesn't grok scale very well.  So Charlatan's post at The Mule Abides is a great help right now.  He takes the great six mile hex and blows it up to seaworthy size.  What you get is a hex like this:
He points out that "Large sailing ships, galleys, and sail boats cover 72 miles in a day." which will work pretty nicely with one hex a day for travel.  So, I took a pic of the Mediterranean made it a layer and compared it to my world map guesstimated what a hundred miles would look like (roughly) and marked it on the map with a dot. Then I got some hex graph paper online resized it to be about right (again roughly) and pasted it on top.  I got this:
Crap, most land is only three days away.  When I cut this map out of the Mediterranean one I did it to hide the real world inspiration and the fact that the world is rather small.  But this may be too small of a section.  Any opinion from you experienced sea dog DMs?  How big should the "saltbox," as Charlatan calls it, be to work?  Weeks of sailing across, months?


  1. Worth pointing out that the 72 mile/day pace assumes that you are 'running fore the wind' to a Broad Reach. IE you are sailing within a 60 degree cone centered on a strong breeze.
    If the wind is blowing south and you want to go north the best you can manage is to 'Close Haul' Tack within about 30 degrees of N (ie NE for 10 miles, then NW for 10 miles, resulting in you moving 17 and a third miles for 20 miles of distance or ~85% of the usual. Also not every culture knows the secret of how to tack against the wind. Many (particularly in the Classical Med) used oars when moving against the wind instead, managing a mere 30 miles a day or so.

    Alexandria to Rome is about 1200 miles NW and the prevailing wind is to the NE, thus sail is possible both ways (mostly)by sailing at a 90 degree angle to the wind. So at 72 miles a day, you'd take a little less than 17 days to travel between the two.
    I'd say that 3 week's sailing, one way, in a good wind, is a decent size for a campaign not wholly centered on Blue Ocean travel.

  2. What Tom said. I think the most important thing would be to add some unpredictability - it's not very simulationist, but how about a 1d6 roll per hex: on an odd number you manage to move forward, on an even number there's no progress (for whatever reason: no wind, adverse winds, you lose your way, breakage), and on a 6 you get a storm, current or navigation failure which blows you into an adjacent hex - possibly the one you wanted. For each 6 you roll on the mishaps table.

    Then I'd say a hex size roughly 2/3 what you have now could work well, so most destinations are about 4-5 hexes (6-10 days) away, and you always have to pack extra supplies. Allows for more mystery, not only about those lost and phantom small islands but about the actual bounds and distances of the players' (unhexed) map.

  3. ...the other thing is, monsoons were/are a huge help in the Indian Ocean because they mean reliable winds for some part of the year. So you can make a pretty much guaranteed run as long as the monsoon's with you. The Med has some seasonality as far as winds go, but it's more like "don't try to leave port during these months" than "once it starts blowing east you're good for 16 weeks."

  4. Sometime I must write up my Goitein for gamers post, about how much fits on a camel, and how long it takes to cross the med in 1100, and (per Chgowitz) tax and toll rates, the merchant's life. It's probably all in GURPS Low Tech, actually. But this post and Chgowitz's make me think that there should be a central resource for a lot of DM's ready reference. Maybe a wiki? I thought that was what Tao of D&D was for a while, but it seems that's more focused on Alexis' campaign.

  5. The only time we did a lot of sea adventuring was running X1 Isle of Dread "back in the day". The Sea of Dread is huge - like 40 hexes across (24 mi per hex) - comes out to something like 13-14 of those 72 mi hexes.

    If you want the salt box to be exploratory, discovering new lands and islands, you'd need a bigger area like the Sea of Dread.

  6. I think Tom's comment about tacking and rowing is spot on: The B/X rules will drop the Argonauts' speed down to 18 miles a day when they have to resort to rowing (4 days to cross a hex). There's a wind conditions table on X64 for daily variance in wind, or the players could just pursue the blessings of Jove and/or Neptune.

    The handling of navigation failure is a little sticky: If the ship has no navigator, it's lost once out of sight of land; if it does, I'd probably want to use a save or attribute check in adverse weather to determine whether the navigator is wrong, so that the navigator has more skin in the game (in the event that it's a player). What do you think?

  7. Awesome comments, all.

    I need to take a look at Isle of Dread. I want the different levels of wind to be few enough to be simple. I want the getting-lost system to be simple too. I liked Paul's, chart for random encounters:

    As far as navigation checks for players, Charlatan, I think you just found the perfect use for Jenga! Staying on course means pulling more blocks, but wait that's a diminishing returns thing, that means the longer they are at it the more chance of failing, so probably not. Hmm.

    My party is in a junk, and those can tack, right? No oars, though. I suppose I should look at the wind directions of the real Mediterranean-- what looks like 3 days sailing on my map might actually take twice that. So maybe I only need to adjust the scale by a little to make the open sea larger. And keep in mind there is more sea past the pseudo Greece in my map.

  8. @Richardthinks- If you've got something send it to Tao. The wiki was conceived to be exactly that sort of central clearing house.

    Even if he shoots you down you (and we) are no worse off, and if he doesn't it may help to start a landslide of contributions we can all profit from.

    I think most of the reason it's got so much of Alexis' stuff on it is that he posts stuff pretty much weekly (and as wiki admin, his stuff gets fast tracked for approval).

  9. Oh, and yes, Junks can tack. They are actually quite an advanced ship design. Their biggest problems stem from the lack of a keel, meaning they rely almost completely on the rudder to keep from sliding sideways in the water. But that is probably more simulationist than you need, or want.

    Although I do wonder what a Chinese(?) Junk is doing in the middle sea. Is this a fantasy version of Zheng He's trading voyage? Or is it an Indian junk blown off course?

  10. Thanks, Tom. It started with my wanting Nidus to be an Orientalist city turned up to 11. So there had to be cogs and dhows and sampans and junks in the harbor.

    Now that I have sort of backed into using the Mediterranean as a model it may seem odd, but remember it's just my model. In this world the Holy Land may be conquered by the "Indians." So I'm assuming it's at least possible that a trader/explorer/pirate junk made it to the Mediterranean at that time.

  11. If you're modeling after the Mediterranean, why not just pick up _City and Guild_ for Ars Magica 5E, or _Mythic Seas_ for Ars Magica 4E?

    Since it's, you know, set in 12/13C Europe? :)


  12. Hi, Ben. I've only ever thumbed through the first edition of Ars Magica. Do you think those books would be useful for an abstract, lighter rules game? Do they include game mechanics, or just background info?