Dr Eric Silverman

UPDATE 1 MAY 2020: Added ‘Playing Symple over the board’ section, and downloads for the Ai Ai .mgl files for large/oblong Symple boards and HexSymple.

Way back in Connection Games III: Havannah and Starweb, I praised designer Christian Freeling’s games but expressed a bit of skepticism regarding his list of six ‘games that matter’:

Christian has invented a tonne of well-regarded games over the years, and he has his own opinions on the most essential ones — namely Grand Chess, Dameo, Emergo, Sygo, Symple and Storisende.  Although I’m not sure I can agree with most of them, personally speaking — that list is mostly games I certainly admire, design-wise, but don’t particularly enjoy playing.

I still stand by most of that — I do admire all of those games, and still I’m not a super-fan of several of them.  But I’m here today to tell you that I was wrong, in fact very wrong, about two of them:  Symple and Sygo.  Today I’ll tell you about Symple, designed by Christian Freeling and Benedikt Rosenau, and in a future post I’ll introduce its descendant Sygo as well.

Full credit for this change of heart must go to David Ploog, who sent me a draft of an excellent article he’s writing for Abstract Games Magazine about games featuring many moves per player turn, with Symple being the star of the piece.  His explanation of the game massively piqued my interest, so I started exploring it via Stephen Tavener’s Ai Ai software — which I’ve recommended many times already, you really should download it!

What I discovered is that Symple is not just an ingenious piece of invention, it is that most elusive kind of ingenious invention — one that you see in action and think ‘how did no one think of this before?’  The core of it is easy to grasp, yet in play it surrounds you with staggering complexity while still remaining manageable.  Having been obsessed with it now for a little while, playing many games, and analysing many others with the AI, I’m convinced that this game is something truly special.  Had it been invented hundreds of years ago, I think today it’d be sat alongside Chess, Go and Shogi as one of the great traditional games.

Enough gushing — from here I’ll explain the game, show off a few example games, and maybe gush a bit more here and there.  In deference to David’s article, which will explain strategic concepts to you far more clearly and expertly than I could, I’ll shy away from detailed playing tips and simply direct you to play it on Mindsports or via Ai Ai and explore it until David’s article is out.

How to play Symple

Symple is best played on a Go board, using standard black and white Go stones.  I’d recommend the full 19×19 Go board (or even larger — more on that later), although for the first few games a 13×13 board or even 9×9 would be a good idea, to get used to the core concepts.  Here are the rules:

1. Each player chooses a colour, Black or White — White always goes first.  Before starting, players should agree on an integer value P, which will affect the scoring at the end of the game.
2. Key definition: a group is a set of horizontally and/or vertically adjacent stones (orthogonally adjacent, in other words) of the same colour.  A single stone is also a group.
3. Making moves: on their turn, a player must do one of the following (players may not pass their turn):
   1. Plant: place one stone anywhere on the board that is not adjacent to any stones of the same colour, which creates a new group
   2. Grow: add one stone to every possible group of their colour on the board, by placing a stone on a vacant point horizontally or vertically adjacent to that group.  If a group has no vacant horizontally or vertically adjacent points, then that group may not be grown.
4. Balancing mechanism: once per game, if neither player has yet made a growth move, Black may grow all of their groups and then plant one new group in the same turn.
5. Move restrictions: if a group grows and the added stone touches another group, then both groups are considered to have grown (meaning the group the new stone touched now can’t grow this turn).  However, two groups may grow in such a way that only the two new stones are now adjacent.
6. Scoring: the game ends once the board is completely full.  At that point, both players count up the total number of their stones on the board, and the number of separate groups they have.  Their final score is the total number of their stones, minus P points for every group they have on the board.

To summarise, in Symple players seek to claim territory on the board for their groups of stones to grow in by first playing planting moves, then growing those groups all at once with subsequent growth moves.  Creating groups early in the game is important in order to claim territory and secure space for future growth, but creating a new group takes an entire turn for just one stone placement; conversely, during a growth turn, a player may place a huge number of stones in one turn, sometimes 10 stones or more during a 19×19 game.  The scoring system gives players a penalty of P points for each group of their stones at the end of the game, meaning that connecting one’s groups is paramount.

Growth turns give players an enormous array of choices.  A typical early-game growth turn might look something like this:

Here White is taking a growth turn, as depicted in the Ai Ai software.  In Ai Ai, groups that have a growth move already chosen are faded out, as in the top left of the image, and new stones are indicated with a ‘+’.  In this instance White has taken advantage of the two-stone separation between the two groups on the upper left to grow both groups in such a way that they are now connected.  Around the other groups, the green asterisks indicate where legal growth moves can be played.  At the end of this turn, White will have played up to a total of eight stones, one for each group.  Note that White could end up only playing seven, if they elect to grow one of the two top-right groups into connection with the other; that would then block the second group from growing that turn, and from then on they would be a single group.

Playing a fistful of stones in one turn is initially intimidating, but these massive multi-moves naturally keep one’s mind focussed on strategy over tactics.  You will find yourself considering the optimal directions of growth to restrict your opponent, facilitate your expansion, and develop opportunities for later connections between groups.  The growth mechanism makes the game feel organic and flowing; more than single stones, you’re manipulating amorphous, amoebic groups that ooze and coalesce across the board.  The feel of this game in play is unlike any other abstract strategy game I’ve played before.

Examples of play

Let’s look at some examples of completed games, to get a better idea of how the scoring system works.  A finished game of Symple looks something like this:

A finished game of Symple on a 19×19 board (P = 10).  Black wins, 128 points to 83.

In this game, the players agreed to play with P set to 10 points.  Black finished with 5 groups totalling 178 stones, for a final score of 178 – (5 * 10) = 128; White finished with 10 groups totalling 183 stones, for a final score of 183 – (10 * 10) = 83.  Black solidly outmanoeuvred White here, connecting more groups together to significantly reduce their point penalty and take the win.  Note White’s unfortunate 1- and 2-stone groups on the bottom right — these alone took 20 points from White’s score!

This GIF shows off the whole game:

The endgame in Symple can be quite challenging and subtle, as in this close game:

A finished game of Symple on a 19×19 board (with P = 10).  White wins, 79 points to 62.

Here both players finished with 10 groups, but White managed a win.  By restricting Black’s ability to grow certain groups earlier in the game, White eventually forced Black to play stones into isolated squares in the late stages of the game, causing significant extra scoring penalties that secured the game for White.  Here’s the complete game in GIF form:

In Symple, managing your growth carefully and strategically is very important, as the final score difference may end up coming down to ensuring that one’s final stone placements aren’t forced to be new, point-draining groups.

The balancing mechanism provides some great tension in the early game, as well.  Black has one opportunity to grow and plant in the same turn, but White knows this, of course, and can short-circuit that chance by playing a growth move earlier than expected.  But growing too early can be too committal, losing an important opportunity to plant a new group in key territory.  This dynamic provokes a pleasing little game of chicken, as both players try to suss out their opponent’s rhythms and strike at the right time — “should I do my double move now, or will White wait another turn to do their first growth turn?”

On the whole, Symple has a great flow to it, and every phase of the game feels consequential.  In the opening, players plant all over the board, attempting to claim space for future growth while impeding the opponent’s opportunities for later connection.  All the while the will-they-won’t-they tension of the balancing mechanism lurks in the background.  In the middlegame, players switch over to growth moves and their groups extend their tendrils across the board, competing with opposing groups for territory.   In the endgame, Symple turns ‘cold’, as players turn from aggressive expansion to cautious growth to avoid getting hemmed in, while trying to force their opponent into positions where they’re forced to plant a stone somewhere unfortunate.  The final result is shaped by key moments in each of those phases, making the whole experience feel cohesive and dynamic.

Playing Symple over the board

Playing Symple is very easy when using a computer program or web-based implementation, since the software will track group sizes and scores for you.  When playing on a real board, however, a bit more effort is required to keep track of things.

A single turn in Symple can require a lot of individual moves for each player, and one can easily get confused as to which group has already been grown.  Most players recommend using a second, easily distinguishable type of token or stone to mark your intended growth moves, and replacing them with normal stones once you’ve decided on all your moves for that turn.  That allows you to think about each growth move without getting confused about which group can still grow.  If you’re using a Go set and want to maintain the austere aesthetic of black and white stones, then consider using Chinese-style Go stones with one flat side as your markers, and Japanese-style double-convex stones for regular plays.

The other aspect is scoring, which in Symple involves a lot of counting.  However, the game continues until the board is completely full, so as David Ploog pointed out in a BGG discussion, scoring can be done quite efficiently: simply count the number of groups for each player, then remove all stones of one of the colours from the board, and count the stones for the other colour.  Since you’ve recorded the numbers of groups, you can freely rearrange the remaining stones into an easily-countable shape, too.  That’s all the info you need to then calculate the scores for both players.  Using this method, scoring a game of Symple shouldn’t take any longer than scoring a Go game.

An eminently flexible game

Alongside the straightforward rules, unique gameplay and immense strategic depth, Symple has some practical advantages that add even more interest.  An important element of the design is that the value of the group penalty P is not fixed, and players can experiment with different values.  Smaller values reduce the emphasis on connecting groups, while larger values make it even more essential.  David Ploog recommends P = 10 for 19×19 games, and in my experiments so far I agree; I’ve also played some 19×19 games at 12, 14 and 16 and have enjoyed those too.  When experimenting with different values, bear in mind that on boards with odd numbers of squares, you should use an even value for P to ensure that draws are not possible.

The enormous multi-move turns of Symple also mean that the game is incredibly scalable.  Symple plays remarkably quickly even on 19×19, since each turn can easily provide 10 or more stone placements — and these mechanics tend to emphasise strategic concerns over tactical ones, which helps to keep the game from bogging down with excessive calculation for every stone placement.  As a consequence of these unique properties the game plays well even on ludicrously large boards.  Here’s a game I played against the AI on a 37×37 board:

A game played against the AI on a 37×37 board (P = 18).  I won as Black by only 3 points, with a final score of 434 to White’s 431.

This game was huge, but still surprisingly playable; in the middlegame we were often placing well over 20 stones per turn, so even with 1,369 squares to fill the game moved at a good pace.  The result came right down to the wire — I won by only 3 points.  If you’re bored you can watch the whole game in animated GIF form here.

I’ve definitely never played an abstract game before Symple that could take place on a board that large and remain playable and fun.  Go is one of my all-time favourite games, but play on the standard 19×19 is already very challenging; I’d never go near 37×37 Go.  Symple’s mechanics mean that the board fills quickly, and strategy reigns supreme over tactics, and so even on boards this large one doesn’t feel too hopelessly confused.

I’ve also found that Symple presents some interesting challenges on rectangular boards.  Here’s a game played on a 19×29 board:

A game of Symple on a 19×29 board (P = 12).  Black wins, 117 points to 110.

This was a test game between two AIs, played when I first modified the Symple file in Ai Ai to permit rectangular boards.  Note that both players took advantage of the strange board geometry, growing huge groups horizontally across the board.  You can view the whole game in GIF form here.

Note that Ai Ai by default only supports square boards up to 19×19; I have modified the Symple.mgl file in Ai Ai to permit rectangular boards with sizes up to 37 in either dimension.  You can download the .mgl file needed in this Google Drive folder; simply add it to the ‘mgl’ subfolder within your Ai Ai folder, and it will appear in your games list.  The file you need is called Symple-rect.mgl.

All my tests of weird board dimensions have confirmed that the core mechanics of Symple are not just clever and elegant, they’re also extremely robust.  The game remains interesting even with bizarre values of P, or when played on extremely large boards or weirdly-shaped boards.

HexSymple

Speaking of weird boards, it turns out that Symple is also incredibly good on hexagonal boards, too.  Christian Freeling calls it HexSymple, and in this variant the game is played on a hexhex board (a hexagon-shaped board composed of hexagonal spaces).  The rules are identical to regular Symple.  Here’s a game played on a hexhex board with 12 hexes to a side (that’s 397 hexes in total):

A completed game of HexSymple on a hexhex-12 board (P =10).  White wins with 153 points to Black’s 124.

In this game White managed to constrain Black’s growth along the left edge and take the win.  HexSymple has a very interesting character — the board geometry means that cutting off groups is more difficult than on the square board, since all hexes have six neighbours instead of four and there are no diagonal cuts possible.  The game feels very expansive as a result, with ambitious connections snaking across the board in every direction.  Here’s the full game in GIF form:

Just as in regular Symple, HexSymple is incredibly scalable, and I’ve played a few games on very large boards because I am a bit crazy for large boards.  Here’s one on a hexhex-25 board (that’s 1,801 hexes):

A completed game of HexSymple on hexhex-25 (P = 30).  White wins, 643 points to 588.

You can see here how the expanded connectivity of hexes makes truly enormous groups possible; check out White’s gigantic group stretching from the top right all the way around the board to the top left!  You can see the whole game in GIF form by clicking here.

On the whole I highly recommend HexSymple.  The board topology creates some interesting wrinkles in play, but the overall strategy remains broadly similar to regular Symple.  The result is a fascinating variant that works as a great change of pace, and stands up as a great game in its own right, too.  I haven’t yet seen a consensus on what good values of P might be for different sizes of boards, but in my experience you can safely use significantly larger values than on similarly-sized rectangular boards and get a similar experience, due to the increased connectivity between hexes.

Note that HexSymple is not implemented in Ai Ai by default, but a simple modification of the regular Symple.mgl file makes it possible to play.  You can download the file you need, helpfully titled HexSymple.mgl, from this Google Drive folder.  HexSymple of course has its own dedicated page on Mindsports, and you can play the game online there too.

A modern classic

In the very crowded field of modern abstract strategy games, Symple (and HexSymple) are rare specimens that feel like classics.  In some alternate universe, I imagine Symple having frequent high-level tournaments, with a professional player scene, ample literature on high-level play, and an online community with millions of players.  Perhaps in the not-too-distant future this may come to pass in this reality, too.  In the end I agree with Christian — this is certainly a ‘game that matters’.

Sometime in the (relatively) near future, I’ll post a follow-up to this and introduce Sygo, a combination of Symple and Go and Othello-style piece-flipping captures that seems like it shouldn’t work, but totally does.  Like most fans of Go I’m not very keen on most Go variants, because they normally just disturb the elegant balance of simplicity and depth that makes Go so seminal.  But Sygo feels different enough to have its own character, and HexSygo even more so.

Before that, I owe you all a couple of Shogi posts which are still in the works.  I’m pleased to say that the Japanese Chu Shogi Players Association — Chu Shogi Renmei — has sent me a treasure trove of historical information on the game.  It’s all in Japanese, of course, so it will take me some time to read, but with any luck I’ll have some interesting information to report further down the line.

In the meantime, please do yourself a favour and whip out your Go set, get yourself on Mindsports, download Ai Ai, or preferably all of the above, and give Symple a try.