Update - Alpha 6 Nearly Done

in Ren`Py RPG Battle Engine Newsletter


  1. Update & Upcoming release details
  2. Unanswered Emails
  3. Commercial Licensing


Progress on the Ren'Py Battle Engine has been pretty slow of late, for a variety of reasons. In the last few months I've changed jobs and I'm in the process of moving house, and that's taken a lot of my time and energy... and we're almost done on a big release at work of late, which has meant I've not wanted to take my laptop in and code the Battle Engine in my lunchbreak. That doesn't mean I've been doing nothing at all, though, and there are a whole raft of new features almost ready for release!

In the upcoming Alpha 6, you can expect to find:

  • Various bugfixes - including a fix for my #1 most-hated bug, the panning/slide graphical issue.
  • Various minor improvements and additions to the framework, which make things easier for anyone doing custom stuff (and for me, of course).
  • Improved implementations of GetRange, meaning square- and hex-grid battlefields perform better.
  • 'AreaScenery', meaning you can mark out a rectangle that your scenery sprite occupies. This allows you to quickly block out areas of the battlefield without actually removing them from the battlefield (which makes it impossible to draw line-of-sight through them) and also have fighter sprites correctly appear in front of or behind the scenery sprite in all cases.
  • A customisable Experience system, along with the usual bouncy XP numbers and built-in behaviours.
  • Some UI improvements, such as the option to re-order skills in skill menus (as opposed to them appearing in alphabetical order).
  • Battle-related preferences to prevent rollback, skip attack animations or skip movement animations.
  • A system of conditions and events which allow the creator to set up more-complex mission objectives than simple "wipe out the enemy" missions.

Several of these have come more-or-less direct from the development of Tristan and Iseult, which was the first completed game using the engine, and a pretty successful exercise in showing up all the parts of the engine that needed a bit of extra work! Since T&I was a NaNoRenO game and completed in a very short timespan, lots of the features needed extra work to make them generic enough for anyone to use in their games, which is another reason alpha 6 has taken a while.

(I've decided to leave out enhanced-AI for now - that needs a lot of work, and the basic stuff is fine for most battles.)

Now, on one hand, all of those features are at least complete enough to work in my test battles, so the release is pretty much ready in core-functionality terms. The problem is that I haven't had the time yet to write demos for all the new functionality - and in absence of proper documentation, I expect most people would appreciate demo code!


Another related thing: I have to apologise to several people who've emailed me regarding the battle engine in the last few months who I haven't got back to. If you haven't received a reply, it probably means that you asked something that I can't easily answer in a ten-minute email and I didn't find the time to give you a proper response before your question slipped off the front page of my inbox and I forgot about your question. I'm sorry - I realise this makes me a horrible, horrible person!


That said, the most common question I've been asked is whether people can use the battle engine in a commercial game. Now, the short version is "not without asking permission, since it's released under a non-commercial license"... which I realise isn't particularly helpful if I've not replied to your email asking permission!

It's perhaps a bit of an odd quirk of my personality, but I tend to see the distinction between making something available for others to use for free and agreeing to allow someone to use it in a commercial venture as one of endorsement. If someone releases something for free then nobody loses out giving it a go, but once you take someone's money for your game, you owe it to them to make your game worth their money. I realise it isn't the proper happy-capitalist way to go about things, but if I'm going to allow you to use my work in a commercial game, it feels to me like an endorsement of your game; as such I want to be happy that your game is going to be worth people's money. I've already let one guy use the engine commercially, because he's someone who's made good, interesting games in the past, and I'm confident that he'll be able to make something interesting and engaging.

Expressing that is the main reason I've felt unable to quickly answer people's requests for commercial licenses in the past. If you want to ask permission to use the battle engine in a commercial title, then please - make me aware of work you've done in the past, give me an idea of the kind of game you're going to make, and so on: give me enough information to work out whether it's something I feel comfortable giving my tacit endorsement. I apologise for being awkward about it!

Details about the Ren'Py Battle Engine can be found at the website here:

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please release a tutorial on how to program the different types of games, im having alot of trouble 1.understanding the file codes and how to alter them, 2.which file are used to make sertain gamep ie so to make the engine work for a path game OR/and a hex based game so the size is lower by cutting unneeded files. im having huge amounts of trouble recreating the game i want using my pics, i keep going into a loop of errors. i hope for the improved use of this engine that we soon see a tutorial like that in renpy either seperate download or in a optional with the next engine release.

As it happens...

As it happens, I'm in the middle of adding some things to the engine which should make it a lot easier to script battles - I'm deliberately holding off on tutorials until after I'm finished with this, as otherwise I'd have to re-write them entirely afterwards anyway, and it would just confuse people.

Hopefully it shouldn't be much longer, though! I fully intend to write some quick example games and tutorials once I've got the next big bit of work out of the way.

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