Using Mats: Please Share Your Experiences

The new Cargo Mat trait looks like an extremely nifty feature with lots of versatility.

I was previously planning to use Map Windows for company charters in a module for an 18xx prototype, but now I’m considering using Cargo Mats for company charters.

What is your experience with Cargo Mats?
Do Cargo Mats stack when loaded?
If so, does the cargo get “confused” as to which mat it is on when stacked with other loaded mats?
If loaded Cargo Mats stack, can they be stacked in order of their names?
Can Cargo Mats start a game Pre-loaded with pieces?
Can a Cargo Mat hold a deck as cargo?
Can pieces or decks starting on the Cargo Mat be “assigned” a particular spot like an At Start Stack on a Map Window?
How difficult is it to unload a piece of cargo and directly move that former cargo to another Map Window? Could this be done in a single drag action like moving a piece from one Map Window to another?
How difficult is it to load a piece of cargo?

Physical 18xx games have company charters which function like a player board for a company. Each company that is active in a game has a director, or president, who is one of the players who makes all the decisions for the company, and manipulates the company’s pieces. The company charter is usually located in the player area of its director. Items that are commonly kept on company charters include: the cash in the company’s treasury, cards or pieces representing trains currently owned by the company, station tokens which are pieces representing train stations that may be placed on the map board, and cards representing stock certificates owned by the company. Generally, a company’s director is the player with the most shares of that company’s stock. Since stock is bought and sold during the game the directorship of a company can change, and if it does, the charter with its contents is usually moved to the new director’s play area.

Before Cargo Mats were introduced I was planning to use Map Windows for company charters, but now I’m wondering if Cargo Mats might be more appropriate. Either way, I’m planning to: abstract the company cash as explained in, use cards for the trains and stock certificates, and use pieces for the station tokens with the station tokens and possibly the company’s stock certificates starting on the charter (the specific prototype starts with incremental capitalization). If I use Map Windows, I’m planning on having At Start Stacks for the station tokens and a deck for the stock certificates. I’m not sure how this would be handled using Cargo Mats.

Map Windows are easy to display or hide, but this prototype has 48 companies needing charters. So that would be a whole lot of Map Windows (the module will also have a Map Window for the board, stock market price chart, the bank, the box (out of play area), and each of seven potential players). Most likely there would be less than 30 companies active at any one time. So if Cargo Mats were used, charters for companies not currently in play could be kept in “the box”, a Map or Chart Window for storing components not in play, and not clutter the play area. Also, using Cargo Mats and keeping inactive ones in “the box” would reduce confusion about about which companies are active.

A charter as a Cargo Mat in the director’s Map Window would likely provide a stronger visual association with the director than the director’s name displayed in the company’s Map Window, if that were used as a charter.

“A penny for your thoughts.”

My understanding from here is that mats by definition cannot stack.

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Mats never Stack ever. Sorry, there was just no way around that. To make Mats work at all, we had to interfere with the standard Vassal stacking mechanism, which prevented the possibility of allowing any sort of standard stacking.

The only exception is that Mats with no cargo loaded may be loaded into a Deck.

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Once a Cargo is loaded onto a mat, it is ‘locked’ to that mat and is not affected by the placement of other mats in the same or nearby locations. Mats holding cargo can’t stack, but they can be placed over other Mats holding cargo.

They don’t stack.

Only if you set it up that way as part of a pre-defined setup. You cannot create loaded Mats via at-start stacks.

No, Decks are fixed in place on the Map.

You can create individual mats and individual cargo pieces in the correct locations via at-start stacks, but the cargo will not be loaded on the mats. However, you could specify a game-start GKC to force all cargo on the map to load onto any mats they happen to be sitting on.

Cargo is just moved like a normal piece by Drag and Drop or Send to Location traits etc. If the end location of the move is not on the Mat, then the cargo is automatically unloaded from the mat. You can also force a cargo to unload in it current location via a command key.


Cargo loads automatically when moved if it’s movement ends on a Mat.

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Brent, Thanks for all the details. It looks like I might need to get a bit more creative than I was anticipating, but using Cargo Mats as charters does look doable and possibly a better solution than using Map Windows as charters.

Joel, I appreciate your response as well.

I have so far used Mats in:

  1. A block wargame, Napoleon’s Triumph, where the commanders are mats that can carry units as cargo. Mats were really helpful, as the blocks have 120 rotation facings, so rotating a whole corps together while keeping their positions relative to each other saves a lot of tiresome busywork.

  2. A logistics game, Roads & Boats, where the transporters are mats that can carry stacks of resources as cargo. Being unable to have a transporter carry a transporter is a small price to pay for the convenience of loading and unloading cargo on mats.

  3. Card games. I’ve yet to do it, but Pax Pamir 2e will replace the current arcane system used to keep tokens on cards with mat cards and cargo tokens. A small improvement, but a nice one (mats and cargo would have saved a ton of time that went into creating the current complicated system).


I tried your Roads & Boats module for a few rounds to see how I might like the game. The module is pretty slick, but the game feels fiddly, especially since I was playing solo (I generally get bored playing any game solo). I had a few problems getting the loads onto and off the donkeys. I think it had a lot to do with the relative sizes of the loads, donkeys and hexes. I think the mats definitely improve the play experience.

Thanks. I don’t make the games, I just make the UI.

(But Roads & Boats is a good game of logistics warfare. Well worth trying it out in that sense, not so much as a puzzle.)

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Thanks again to: @JoelCFC25 , @Brent_Easton , and @Benkyo for responding and helping me to better understand Cargo Mats. In reading the reference on the Send to Location trait (, I’m now thinking of having the pieces that I wanted to have start on the charter (Cargo Mat) start in some window then use a trigger to send these pieces to the charter, using the Send to Location of another counter with the charter as the other counter, when the charter is moved from the start window to a player’s window. I was thinking that I might be able to used the additional X an Y offsets to get these pieces where I want them on the charter.

If this is a good way to do this, I wonder if there are any examples to look at.

Thanks again.

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Once Almoravid actually ships from GMT (the production copies are apparently on the sloooooow boat from China), the Almoravid module uses mats extensively. It’s part of the Levy & Campaign series, so if you’ve seen Nevsky you’ll get the idea. So “watch this space” :smiley:

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I mean yeah, there should be no problem with doing that.

I don’t have specific examples using Mats, but it is the kind of thing I do a lot to set up player pieces, and there’s no reason it wouldn’t work with Mats.

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I finally got around to building the charters (mats) and stock certificates (cargo) that will go on the charters in the game and adding traits to manipulate them. I built the charters and the stock certificates to be cards that start in decks.

I learned that loading a mat while it is in a deck leads to unexpected behavior:

  1. The mat and cargo can disappear
  2. The mat and cargo can become unselectable

Decks and mats with cargo don’t mix. That doesn’t sound unexpected.

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@Cattlesquat this sounds like a good thing to warn about in the Mat documentation.

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Unloaded Mats can start in or be added to a Deck.

Loaded Mats cannot be placed into Decks.

Exactly how are you trying to ‘load a Mat while it is in a Deck’? That isn’t really possible. If the Mat is showing as the top image of the Deck, It’s still a Deck, not a Mat, so if you drag any Cargo onto it, the Cargo will most likely go into the Deck.

Joel, yes, we are updating the reference manual to note this limitation.

My mats start in decks. I revised the module to send the desired mat to another location out of the deck via a Send to Location trait. Then send the cargo onto the mat, again via a Send to Location trait. This works fine.

Formerly, I issued an up arrow Global keystroke to the particular mat in the deck to move it to the top of the deck. Then sent the cargo onto the mat, via a Send to Location trait. This seemed to work fine when there was only one mat in the deck, but gave trouble after adding a second mat to the deck. After thinking about it for a while. I remembered reading your comments above and decided to try moving the mat out of the deck before loading it.

I just wanted to share my experience to help others either avoid this mistake or recover from it quickly.

Thanks for all you do to help make VASSAL so versatile and friendly to those of us not hip to the current IT ways.