Show HN: Pressure – a simple 2D board game in JavaScript

(ilmenit.github.io)
6 points ilmenit | 3 comments | 02 Apr 25 11:57 UTC | HN request time: 0.6s | source

I'm a fan of minimalistic design and I tried to make an "easy to learn, hard to master" 2D board game.

Pressure is played on a 5×5 grid with 12 tokens total. The key mechanic is a "push" feature where tokens can displace entire lines of other tokens if there's an empty space at the end of the line. When opponent tokens are pushed, they become inactive for one turn. Capture occurs when tokens are surrounded on all four sides.

After analyzing gameplay data, I found Pressure has an average branching factor of 11.5, which is higher than Othello (10) and Checkers (2.8), though lower than Chess (35). Its game tree complexity is approximately 10^57, placing it remarkably close to Othello (10^58) and much higher than Checkers (10^40), despite the smaller board size.

The state space complexity appears to be in the range of 10^20, comparable to Checkers, which is notable given Pressure uses a 5×5 grid versus Checkers' 8×8 board. Chess and Othello have higher state spaces at 10^44 and 10^28 respectively.

What's computationally interesting is how the push mechanic generates this complexity. About 27.5% of all moves involve pushing, which creates a multiplicative effect on the decision space. Each push can reposition multiple tokens simultaneously and create cascading positional consequences beyond what the compact board size would suggest. I've found the average game length is approximately 50 moves, similar to Othello (58) but shorter than Chess (70) and Checkers (70).

Let me know what do you think about the game.

1. EdgeExplorer ◴[02 Apr 25 16:29 UTC] No.43558465[source]▶
Avid go player with some basic familiarity with other classic abstract strategy games here.

There are some interesting ideas here but it feels like it's lacking a driving force pushing the game forward. It seems like the players can just keep rearranging their pieces in their own area refusing to engage and risk capture. Retreat seems to often be a sensible strategy.

Perhaps this is most similar to chess but in chess if your opponent just moves back and forth you can easily line up an unstoppable attack while they are messing around. It's unclear here how to avoid the situation where the opponents just dance around each other making sure they never get captured.

Could also compare to Stratego where there just isn't anywhere to retreat to, forcing players to engage.

Other abstracts like go and Othello are always adding pieces to the board so there's no way to stall or slow play the game.

replies(1): >>43568880 #
2. ilmenit ◴[03 Apr 25 12:52 UTC] No.43568880[source]▶
Thank you for the feedback! I was thinking about the force forward mechanic and as it exists in mentioned game. In Pressure stepping back is defensive until reaching the edge of the board. The biggest problem with the current design I have with endgame when it's balanced to 1 token left on each side. This could be a draw, because it's in most of the cases is not possible to lead to surrounding the leftover token. With 2 to 1 left still (depending on a board setup) it's possible to dance around to avoid capture. Do you have some proposal that would work in this game?