Monstrous Logic Monster A.I. - Enemy AI for TTRPG Combat



Hello everybody. Hard to believe 5 months ago I shared my pet monster A.I. project for the first time with the Runehammer community, and now I’m proud to announce the release of Monstrous Logic Monster A.I. on itch and Gumroad for $4.99.

Monstrous Logic is an easy to use, highly compatible system for using automated enemies in your tactical tabletop role-playing games. It’s ideal for prep-free game sessions, solo, and GM-less games of your favorite tabletop RPGs, and for players who want their games to have the feel of a Strategy RPG like Final Fantasy Tactics or Into the Breach.

Here’s some kind words from professional indie RPG designers about Monstrous Logic:

“I’ve been waiting for something like this for ages. Brilliantly designed, easy to use, and applicable in almost any system.” - Dai Shugars, GMDK

“Yo anyone who ever complains about prep: this is a nifty tool” - Fiona Maeve Geist (Mothership RPG, Dead Planet)

You can buy Monstrous Logic at the links below

And if the cost is a hardship for you, please claim a community copy on the Itch store page or at this link

Update: Monstrous Logic is now available on DrivethruRPG


The download button for the community version doesn’t work.


Oh dear, I checked just now and it should be working fine on both Gumroad and Itch. It may be an issue with your browser, or you can try the other site since there are still community copies available on both.


Could you tell me a bit more about how this product works?


It appears to be a simple d6 selection action system.


This isn’t true. The hex symbol does not indicate a six-sided die, but a rather proximity condition. We check to see if there are any targetable enemies within that many number of spaces away from the monster. If that is the case, the condition is fulfilled and the monster performs that action. It’s a very similar system to the one used in the board game Sword & Sorcery.


Ah ok. I don’t think most people use spaces with ICRPG I know I don’t.


Gladly. In Monstrous Logic each monster type has a unique A.I. scheme containing its stats and A.I. behaviors. A monster chooses its actions based on fulfilling the condition tied to that set of actions. A condition can be a special condition such as “If this creature has half or less HP”, or it can be a proximity condition (symbolized by a hex with a number or range of numbers in it). With proximity conditions, we check to see if there are any targetable enemies within that many number of spaces away from the monster. When a condition is fulfilled, the monster performs that action. It’s a very similar system to the one used in the board game Sword & Sorcery.

The second half of the rules are the ones for pathfinding. These were lifted liberally (and improved upon) from the boardgame Gloomhaven. Gloomhaven has a robust set of rules that control pathfinding and movement, but that game uses random cards to determine what actions the monsters use. This can make for unpredictable enemies, but anyone who’s played Gloomhaven knows that 25% of the time the enemies do some pretty nonsensical things. Monstrous Logic fixes that problem by applying a deterministic set of A.I. behaviors to the monster’s actions. The monsters make their decisions logically.

It’s really rather elegant and easy to program your own A.I. I’ve even included a guide in the rules for making your own monster A.I. using Monstrous Logic.


Oh that’s okay, in fact under the variant rules section I’ve included rules for converting spaces to abstract distances like close, near, and far. It’s really quite easy to hack Monstrous Logic to work with your preferred systems.


Then you’ve thought of everything. :grinning:

I’ll have a proper read sometime soon


Well thanks a lot, this looks interesting!! :smiley:


Great stuff, I might use this in my upcoming game. Only thing I’m not keen on is the priority targeting e.g. “most HP” or “most gold”. Seems like the monster acting on meta knowledge it would/should/could not have. I’d be inclined to establish with the players before a session “which of you looks beefiest / richest / etc” and establish an order of targeting priority beforehand. Otherwise, awesome :smile:


Thank you so much! I think metaknowledge is an interesting topic, and one I don’t personally consider that often since I almost always play with the monster A.I. using open information.
I will say this, you should absolutely set expectations with your players at the beginning, and there will be a bit of a learning curve of course, but if they’re into the idea I think you and your players will really enjoy playing with ML. Thanks again.


Monstrous Logic is now available on DrivethruRPG


Woohoo! This is awesome! I’m going to pick this up to see your cool work. :slight_smile:


Aw thank you. And if you like it please leave a rating (helps with the algorithms and gets it noticed). And if you feel strongly about it one way or the other, please leave a review so that others can decide to buy.


Some free advice, share this on as many Solo RPG sites as you can find. I know Reddit has one, BoardgameGeek, you may want to mention it on as well. For people like myself, that play solo at times, a system like this can be of great use!


That’s awesome advice : ) That reminds me to make a RPG Geek entry for my game tool. I hadn’t even thought of looking in the BGG forums. Thank you, and I hope you use Monstrous Logic in your games!


Great job.

I do a bit of this intuitively. But I am seeing how this can really help.


A lot of people had a lot of good to say so I bought a copy. Great stuff! This will really help in my game.