Great game, I love it! I hope the author is collecting juicy analytics. They would be useful if they ever want to bundle 100 levels in order of difficulty and release this as a Steam game (which I would absolutely buy!)
I don’t think the gates should animate up into the air. It breaks the visual logic of 2D for no benefit. It’s subconsciously confusing to see a gate I place in one cell move to occupy pixels in the cell “above” it.
I look forward to future days introducing new mechanics as well. Can I suggest a few, based on dynamics?
- Food! The horse moves on every turn towards an attractor. Have a hay bale / giant sugar cube in one corner fall off the back of a truck / helicopter :) Horses start out dumb and move directly towards the goal before backtracking. Smarter horses path find the shortest route to the goal.
- Goals! Now that the horse is moving, get the horse into a static horse box / cattle pen cell by strategically placing fences so that the path it takes towards the food involves walking onto the goal square.
- Floods! Water encroaches from the edges on a turn by turn basis. Not only do you have to contain the horse, you also have to hold back the flood.
I think you should change the cherries to a battery and call the game Correct Horse Battery Stable.
Use staples instead of walls as barriers.
Or the cherries could be a delicious pastry or PBJ-like treat: _Collect Horse Buttery Stable_...
I found the optimal solution for day 8 by hand, that was fun!
My algorithm, by hand, was as such:
1. Start with the smallest possible valid solution (1)
2. Expand slowly, and each "step" (like, moving a wall or two around to "obvious" spaces) must be a valid solution (this brings you to 40-60 score, depending on your choices, on day 8). Continue to step 3 once you can't see anything obvious.
3. Look at possible places where you could expand, but need 1 more block. You'll find one eventually.
4. See if you can spare any walls anywhere, using diagonals for example. If so, place the solution from 3 and go to 3 (repeat). If not, go to 5.
5. Count or estimate the squares gained by doing your improvement from 3. See if you can reduce your score by less than that, pessimizing your solution, to gain 1 wall. Once you've found one, go to 3.
That got me to the optimal score within 15 mins or so.
I found the same algorithm! The top down solution didn't really work.
Very fun game
Score init should say N/EIGH instead of N/A, otherwise great.
Reminds me of a comic I saw a couple years back about a horse parliament where the horses only voted “neigh”
That's from the Far Side. My mom has had this on her fridge for at least 30 years.
This appears to be it. :)
https://i.pinimg.com/736x/4f/51/e0/4f51e04263a89a008e29668b7...
dead. how in the world does a thought like that come into your mind. i feel like i got 0 in creativity
This is nice, I enjoyed it. Was a couple points off the optimal score for day 8 but when I clicked "Show optimal" I couldn't then go back to see mine to compare. Either way, stretched the brain a bit.
Only nit: fix the walls. They take up one and a half spaces so are confusing, and they're sci-fi steel with flashing red lights. Turn them into one-square-only fences. You use fences to enclose horses, not raptor walls from Jurassic Park.
Yeah, it needs to add a toggle button to let you switch between yours and optimal quickly.
I did figure out that you can get back to yours by going through the past-days menu though.
I mean, the horse does sometimes talk about the demon god if you click on it, so who knows...
lovely, I've created a solution finder for it.
1. Do a screenshot of the grid (try to include walls as well)
2. Open https://enclosure-horse-solution.onrender.com/
3. Make sure the number of walls are correct in the input (bottom left)
4. Press "Solve"
PS: It might crash as it's on the free version of render. I've added a caching layer.
Here's the github so you can run it locally:
https://github.com/langarus/enclosure.horse-solution
clone it and run
make init // make web
There is a level editor with the ability to show the optimal result for a custom level. In theory, one could recreate any official level and reveal the best solution that way. However, I haven't tried this to verify any intentional roadblocks by the developer.
You caching in memory or disk? Redis or db might survive the crashes and reduce future ones
on disk, so basically I'm trying to save the image of a solution and reuse it if the same quiz is required. So instead of recomputing the result just return the same image.
Got it. Is that cache surviving the crashes?
I think Cloudflare r2 has a generous free tier. You can also technically store images in redis I think. anyways, thank you for making this, really cool!
curious question from a non-programmer - are you checking against the exact same image (i.e. hashed), or is there an easy way of trying to match an image to a very similar one you've seen before?
Not OP, so I don't know what their website does, but there is a technique called "locality-sensitive hashing" that gives the same hash for similar items instead of exactly the same ones
I see some of you are already crashing the server. :melting: try to run it locally if you can't get the result via render
I think this problem is called the maximum-weight closure and can be solved as max flow. You want to find a cut between source (horse) so they were no out-going edges not in the cut (escape routes).
It's not the same problem. First, it's not directed, second it's a vertex separation problem.
Ah yes quite right.
I would like to be able to compare/switch optimal with my solution with single click.
Side by side or a diff view would be great.
I agree. Also, knowing the max score in advance would be better, so you know when to stop/whether to keep going.
I'm happy not knowing myself but the answer can be found easily in DevTools. All the max scores are there (for current and previous days only).
Each time I see a `horse` domain, particularly for entertainment, I remember to `traceroute bad.horse` and smile again.
Love this! I feel like this would get a lot of traction as a mobile app. It's a perfect "I've got five minutes free" game.
Doesn't feel outrageously difficult to put inside a webview?
I am curious on how you would algorithmically find the optimal solution for this kind of problem for much bigger grids. I wanted to do some seed finding in Factorio for the same exact problem using the generated map images, but never found a good solution that was fast enough.
The site uses Answer Set Programming with the Clingo engine to compute the optimal solutions for smaller grids. Maximizing grids like this is probably NP-hard.
Note that traditional SAT and SMT solvers are quite inefficient at computing flood-fills.
The ASP specifications it uses to compute optimal solutions are surprisingly short and readable, and look like:
#const budget=11.
horse(4,4).
cell(0,0).
boundary(0,0).
cell(0,1).
boundary(0,1).
% ...truncated for brevity...
cell(3,1).
water(3,1).
% ...
% Adjacent cells (4-way connectivity)
adj(R,C, R+1,C) :- cell(R,C), cell(R+1,C).
adj(R,C, R-1,C) :- cell(R,C), cell(R-1,C).
adj(R,C, R,C+1) :- cell(R,C), cell(R,C+1).
adj(R,C, R,C-1) :- cell(R,C), cell(R,C-1).
% Walkable = not water
walkable(R,C) :- cell(R,C), not water(R,C).
% Choice: place wall on any walkable cell except horse and cherries
{ wall(R,C) } :- walkable(R,C), not horse(R,C), not cherry(R,C).
% Budget constraint (native counting - no bit-blasting!)
:- #count { R,C : wall(R,C) } > budget.
% Reachability from horse (z = enclosed/reachable cells)
z(R,C) :- horse(R,C).
z(R2,C2) :- z(R1,C1), adj(R1,C1, R2,C2), walkable(R2,C2), not wall( R2,C2).
% Horse cannot reach boundary (would escape)
:- z(R,C), boundary(R,C).
% Maximize enclosed area (cherries worth +3 bonus = 4 total)
#maximize { 4,R,C : z(R,C), cherry(R,C) ; 1,R,C : z(R,C), not cherry( R,C) }.
% Only output wall positions
#show wall/2.Im over 35 years of age. I have 15+ years of programming experience. And I generally consider myself as someone who has good breadth of tech in general. Yet, this is the first time in my life I've heard of ASP. And gosh. I was completely blown away by this as I read more about it and went through some examples (https://github.com/domoritz/clingo-wasm/blob/main/examples/e...)
Therefore, like a good little llm bitch that I have become recently, I straight away went to chatgpt/sonnet/gemini and asked them to compile me a list of more such "whatever this is known as". And holy cow!! This is a whole new world.
My ask to HN community: any good book recommendations related to "such stuff"? Not those research kinds as I don't have enough brain cells for it. But, a little easier and practical ones?
Thanks..
The pre-machine-learning formulations of AI focused on symbolic reasoning through the dual problems of search and logic. Many problems can be reduced to enumerating legal steps, and SAT/SMT/ASP and related systems can churn through those in a highly optimized and genetic manner.
Has to be my favourite comment, haha!
Nice, you don't see clingo mentioned often. We use it in the Spack package manager for resolving dependencies [1]
[1] https://github.com/spack/spack/blob/develop/lib/spack/spack/...
There's probably an FPT algorithm using important separators (4^k).
Constraint programming seems to be a fitting approach. Input would be number of walls, and the location of lakes. The decision variables would be the positions of walls. In order to encode the horse being enclosed, additional variables for whether horse can reach a given square can be given. Finally, constraints for reachability and that edges cannot be reached should ensure correctness.
Yes. CP SAT crunches through it in no time, but of course larger grids would quickly make it take much longer.
See
https://gist.github.com/Macuyiko/86299dc120478fdff529cab386f...
I don't believe this works in general. If you have a set of tiles that connect to neither the horse nor to an exit, they can still keep each other reachable in this formulation.
Yes, this is the major challenge with solving them with SAT. You can make your solver check and reject these horseless pockets (incrementally rejecting solutions with new clauses), which might be the easiest method, since you might need iteration for maximizing anyways (bare SAT doesn't do "maximize"). To correctly track the flood-fill flow from the horse, you generally need a constraint like reachable(x,y,t) = reachable(nx,ny,t-1) ^ walkable(x,y), and reachable(x,y,0)=is_horse_cell, which adds N^2 additional variables to each cell.
You can more precisely track flows and do maximization with ILP, but that often loses conflict-driven clause learning advantages.
> algorithmically find the optimal solution for this kind of problem for much bigger grids.
Great, now I've been double nerd-sniped - once for the thing itself and another for 'What would an optimiser for this look like? Graph cuts? SAT/SMT? [AC]SP?'
I'd bet it's NP-hard. The standard reduction to a flow problem only tells you if a cut exists (by min-cut max-flow duality), but here we want the cut of size at most N that maximizes enclosed area.
The Leetcode version of this is "find articulation points", which is just a DFS, but it's less general than what is presented here.
I think it's NP hard, maybe from Sparsest Cut. But you could probably find the min-cut and then iterate by adding capacity on edges in the min cut until you find a cut of the right size. (if the desired cut-size is close to the min cut size at least).
It's NP-hard from Minimum s–t Cut with at least k Vertices. That's the edge version, but since the grid graph is 4-regular(-ish), the problem is trivially convertible to the vertex version.
I think there should be some graph algorithm for this, to find a bottleneck in a graph
My 10 year old loves this game. He started playing it Wednesday or Thursday of last week and basically all of his screen time. Both trying to optimize and the level design scratch an itch that few games do
I did Day 8 - I don't know if Perfect means I got the most optimal score, I do show up at the top of the graph.
https://enclose.horse Day 8 PERFECT! 100%
If you click on "View Optimal", it shows you the optimal solution which should be identical[0] to yours for "Perfect".
[0] I'm assuming, possibly quite wrongly, that there's only one optimal solution per day.
I don’t see any View Optimal button. Is it present in Mobile ?
I don't see this button either (desktop) but searching the HTML gives a <script> that says
window.__LEVEL__ = null; window.__DAILY_MODE__ = true; window.__DAILY_LEVELS__ = [{"id":"FswXDo","date":"2026-01-06","dayNumber":8,"optimalScore":86},{"id":"6UV4Yw","date":"2026-01-05","dayNumber":7,"optimalScore":95},{"id":"VfWi_1","date":"2026-01-04","dayNumber":6,"optimalScore":77},{"id":"CNtGPI","date":"2026-01-03","dayNumber":5,"optimalScore":116},{"id":"tnLvlG","date":"2026-01-02","dayNumber":4,"optimalScore":51},{"id":"Qn9vLs","date":"2026-01-01","dayNumber":3,"optimalScore":74},{"id":"Kj7mXp","date":"2025-12-31","dayNumber":2,"optimalScore":90},{"id":"E03KkY","date":"2025-12-30","dayNumber":1,"optimalScore":68}];
Results, then scroll down a tiny bit.
I'm pretty sure the author got the domain first and then designed an (awesome) game around it.
Which came first -- the game or the domain name?
Generally the idea of the game, then the domain name, then the game.
i have soooo many domains i’ve paid for for years that will now get sites because of the fact i can code at 10x+ now.
i like how this was mildly downvoted for some reason
Cool game, but I don't like how you get only one chance. Even returning to the page, you can't try again to beat your previous score. No replayability value at all.
The one shot per day provides a reason to sink your teeth into one board.
I love Wordle but I found it unplayable when I used that Wordle archive site to play infinite games since there was no reason to think deeply about the 10th+ round I was playing in one sitting.
It shows you what the exit routes are, what your score will be, and you can move the gates around as long as you want, so the means of finding the maximum area are entirely within your grasp.
But you have no idea what the optimal solution is, are you 1,10,50 away from it. Would be nice to have some indicator of how close you are before you submit, though I guess that's intentional.
I believe that’s the point. I had the optimal solution for some time but was convinced there was something better. Eventually I submitted, and seeing the perfect score was more thrilling after convincing myself I was an idiot.
If it told you how close you were then you could just brute force your way to a perfect score every board by trying each square.
I disagree about the replayability aspect. It‘s a daily challenge, so come back tomorrow. I quite like it.
I seriously don't get the idea behind daily challenges unless you want to keep users hooked to extract some value from them, but that doesn't seem to be the case here, as there are no ads.
Just show all the different levels at once.
That's fine. So these kind of games aren't for you, then. Remember crosswords in newspapers? Yeah, think of it like that. You don't get hooked until you cannot let go, you get a limited chunk served each day. Same with Wordle.
> It's condescending to the users and feels like a power trip.
condescending (adjective): having or showing an attitude of patronizing superiority.
I don't really see how a once-a-day puzzle is condescending, unless it's a "You can't be trusted to regulate yourself so I'll do it for you" type thing. Adding a dictionary definition like above, however, probably is condescending :)
But I like the one-a-day format because, as other comments have said, you can spend an entire day with just one puzzle feeling important (relative to things that are important).
You can freely make levels and browse other people's levels. The complaining about power trips seems as uncharitable a perspective as you could possibly conceive of, not to mention a bit theatric.
so don’t? others have said they like it, you don’t, move on
I assume that "all the different levels" might not exist yet. The author is probably creating them a bit in advance, and will keep going as long as they're motivated. Having a regular schedule for new releases helps, and doing it daily seems as sensible as any other schedule.
If you click the menu button in the top right you can play all the past puzzles
Click the sandwich icon in the top right, then either Past Puzzles or Browse, and you can play more puzzles. (Or even create and submit your own.)
You can just remove/change walls after having placed all. You see your current score, but can keep iterating.
Yes but it would be nice to see the targets, so you know how far off from an optimal solution you are. I know I'd spend more time looking for better solves if I knew the current one can be improved
Clear cookies?
You get one submit but you can press reset and find better solutions even though you can’t submit it to the leaderboard
You can just test without submitting though?
bruh it’s like Wordle, come back tomorrow
This is a very cool and enjoyable game. I'd be really interested in knowing what framework/library was used to make it. I inspected the source and can see the game is done on canvas, but can't work out more than that.
The canvas API itself is pretty basic. It's not complicated at all to slap graphical tiles onto the screen.
I wouldn't be surprised if they're just rawdogging the canvas API
A very fun game - it took quite a bit of fiddling to get an optimal solution using an LLM. Interesting as I haven't tried using them for 'unique' algo problems much. And then the day 9 puzzle broke my original solver (I had bounded areas that were unreachable to the horse so didn't actually score). Will be interesting to see whether the solver works on day 10.
It would be interesting to be able to change the wall budget for each puzzle to add some variation (with a max limit).
lots of fun! the fact that the walls spill over the square boundaries is very annoying though, i would love to have an option to just make a wall a filled in square without the 3d effect.
Looks like some people have discovered the first "accidental" game mechanic: The horse can walk over cherry fields, but the player cannot place walls on them - so if a level designer places cherries strategically, they can create unblockable paths.
Right now, this is only used for troll levels, but I wonder if you could also use it for some actual puzzles.
I imagine you went searching for domain names and came up with this? I resisted clicking on this top story all day because I thought "how good could that be? "enclose horse" what is that?" Yet, the experience was genuine-slow-forming-smile-of-understanding. This is really good.
Nice game! Out of curiosity, are the daily levels built by hand or algorithmically? Is there some way to measure their difficulty computationally, other than just trying to do it yourself or seeing how many people get a perfect score? I'm also working on a grid-based browser game and both those questions have come up for me, I'm keen to see how other people tackle it.
This is surprisingly similar to a subset of the ARC II puzzles.
The collected answered could probably be used to teach an AI to approach this type of problem thereby gaining some of the cognitive biases that humans have, which is exactly what you want in some cases: An AI that generates human like solutions to hard problems .
Is there guaranteed to be a solution that encloses the cherry? Is Day 8 the first day to have a cherry?
> Horses can't move diagonally or over water.
Ah the famous spherical horse in vacuum
The game dynamic feels a bit like Wordle: One puzzle per day and different solutions that you can compare with others.
I expected the horse to move one tile for each block you placed. I had an elaborate plan to lure it towards one exit and then close it at the last minute... Nope!
John Conway studied similar problems
I did see a game recently which did that (you place a tile, the animal moves a tile, etc.) - possibly on itch.io. I'll see if I can dig it out.
There's an old Flash game called 'Chat Noir' where you have to trap a cat on a hexagonal grid. Here's a copy of it: https://www.hoodamath.com/games/chatnoir.html
Ah, yes, the one I played recently was basically that (except it was a horse, I think.)
A Windows 3.1 game called Rodent's Revenge: https://classicreload.com/win3x-rodents-revenge.html
Video: https://www.youtube.com/watch?v=-r6CnPzTXKE
Damn, the good old days when games didn't have loot boxes, ads, etc...
I remember a game I played on my phone ~15 years ago called "Greedy Spiders". The spiders would move greedily towards something every move, but you could cut strings in their web so they would have to start a new route. So you would kinda have to lure them into going one direction while slowly chipping away at the web, until you could completely cut them off or force them to have to take a longer detour giving you more time to cut more of the web. Quite challenging after a while.
Nice game! I could only play one game but wish I could play previous days' games as well
You can. Checkout the Past Puzzles in the menu (top-right).
Very cool game. Immediately reminded me of pathery, which I can also recommend to everyone who enjoys this.
Seeing tile animations immediately reminded me of Godzilla 2: War of the Monsters on NES.
Enjoyed that.
Removing a block was a bit fiddly on FireFox (Floorp) due to the right click menu appearing when I tried to click on a tile.
Looking forward to tomorrows!
I thought so too at first but you can just left click to remove the wall actually.
I enjoyed it, thanks for making it!
Nice. Reminds me of Rodent's Revenge.
A good game. Possibly the 2048 of 2026.
Leetcode problem
Very fun
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Which AI am I training here?
> I hope the author is collecting juicy analytics.
I hope they're not. Can't we have a few things in this world that are just fun without going and sticking surveillance on them?
'analytics' and 'surveillance' are not the same thing
trying to understand player behavior in the context of a board or video game (though there is some overlap!) is not the same as trying to understand user behavior in the context of social media or purchasing behavior - the data of both of which derive their value from being sold to THIRD PARTIES as a commodity.
being able to tune a fun little video game is not the same thing at all
Collecting analytics like this is effectively the same as play-testing physical board games in-development. People play a game, information is gathered, and the game is tuned in response to that. If zero information were ever gathered, games could not be balanced or tuned for other things like unforeseen problems.
Please, show me a piece of software, or game, that is perfect the first time it is made.
It's effectively the same, except people volunteer or are paid to play test.
This whole industry really needs a lesson on consent.
There are games that let you opt-out, hell even ones that ask you when you first open the game. There are bad apples, but there are plenty of good ones too.
Because using someone else's hardware in a public space is clearly equivalent to using your own hardware in the privacy of your own home.
[dead]
if the analytics lead to an actual game on steam im down
You could just package an arbitrary 100 levels, let the player play them in any order, then give rewards for 10, 20, 30, 40, etc. levels completed/mastered.
This would still benefit from a difficulty rating system or order
something in me loves progressively harder levels
naw im looking to have fun, not cry
> I don’t think the gates should animate up into the air.
I agree! It feels off compared to the overall aesthetic of the game.
Awesome game though! Loved it.
Another thing to try could be to rank people in realtime instead of the one-off submission approach. I do this in https://spaceword.org (create tight crosswords using 21 letters), and I think it's quite motivating to see how you compare to others as you improve your solution. On the other hand, its a bit more taxing on the server, and then you also could not show the optimal solution.
I would prefer not being distracted by that, and not having information on possible solutions before submitting. Trying to find the best solution with added hints like that is a different game. So it should be opt-in.
Cool game! One minor feature request. It would be helpful to have some way to move the entire block of placed tiles around at once to give myself more room in a particular direction.
Thank you! :) If you click the three dots on the left top side of the letters area, you can shift all tiles in a direction.
> I don’t think the gates should animate up into the air. It breaks the visual logic of 2D for no benefit. It’s subconsciously confusing to see a gate I place in one cell move to occupy pixels in the cell “above” it.
I interpreted it as standard "top-down" RPG graphics, where the Y axis always doubles as the Z axis. As such, I didn't find it visually confusing - but it did made playing on mobile annoying, because you often end up targeting the wrong field.
And of course: Buy additional walls using in-game purchases!
(jk)
Sometimes simple things are best. I really like the game as-is.
This is a rather simple game to program. IMO, if you can program, take a few weekends to make your own game based on your ideas. If you can't program, your ideas will lead you to a wonderful learning project.
IMO, the game is great to keep simple, but I’d like to play more levels than just daily, so could see people paying for the ability to play more, like NYT games, and could be part of a suite of game if curated daily by expert vs social curation. The blocks are small though for a small phone with big fingers.
I also wonder if making it GPL and submitting to various *NIX distros would be best. Then it may need to be standalone with random maps created by ML or similar.
It has a very pleasant editor to make + share custom maps, e.g. https://enclose.horse/play/a3OGcW
> I don’t think the gates should animate up into the air.
I think it should go up, otherwise it doesn't look like a wall. It would look like something the horse can step on and run over. For the water it makes sense to be flat flat and that the horse doesn't want to touch it: it is water-shy.
To me the current design doesn't look like anything at all. I don't see a gate or a wall, just two rectangles.
It also conceals the cherries when it’s on the field below them.
+1 to this. It's also visually confusing, the gate looks like it's covering two cells.
Great game! Feature request: add a button that shows my submitted solution. I'd like to be able to compare it with the optimal solution (so it'd be nice if a single tap could toggle between my submission and the optimal).
It would be nice if the “optimal” view visualized both my solution and the optimal one at the same time, like a Venn diagram.