This week I continued with the implementation of the RFC, making all the changes needed to switch from a single session cookie set by finder-frontend, the app which serves the Transition Checker, to a session cookie managed by Fastly, our CDN, and passed to our apps in a custom HTTP header.

We’re using a custom header because it means we can cache based on just that one cookie value, rather than all of the cookies. Since the full Set-Cookie header typically contains a bunch of other things, if we cached based on it then we’d effectively cache nothing.

I got this idea from Fastly’s best practices for cookies.

So, we’ve had to make changes to:

Now we’ve got some common code between collections and finder-frontend, and it’ll only spread to more of our frontend apps. It’d be good to extract that out to a gem or something.

I’ve prepared a bunch of PRs to remove the old cookie and simplify some logic, but I’m off next week.


This week I read:

  • The Kobold Guide to Magic by Ray Vallese et al.

    I quite enjoyed this one. There’s a good mix of topics, giving good coverage to more “magical-feeling” magic (like Gandalf in Lord of the Rings - what are his limits?) and more “technological-feeling” magic, like the rigid spell lists of D&D or the spell-construction rules of Ars Magica. There’s gender-based magic, lost ancient magic, traditional Irish folkloric magic, magical cabals, secret societies, and so on.

    The “Why I Hate Teleport Spells” essay was good. It’s about the problems caused by long-range teleportation (hundreds of miles), and how you can fix that by either switching to short-range teleportation (tens of miles) or a magical waypoint system:

    • The party can just teleport past the Big Bad’s defences.

    • Slow overland travel gives opportunities for additional adventure hooks.

    • The sense of scale goes away, everything feels closer together, and so it feels less epic to cross huge distances.

    • The GM can’t easily pose dilemmas where the party have to choose between multiple objectives because they can’t do all of them in some time limit.


I put an impassable obstacle in front of my Call of Cthulhu group. Naturally, they overcame it, and one of them even said “that was a good puzzle!”

I got my own back though, they then spent a while talking to a crazy man who claimed to have magical powers, but was insulted by their doubt when they asked him to demonstrate. Eventually he relented, and agreed.

One of the PCs cautiously approached the stone circle, watching out for some sort of magical force pushing them back. They raised their foot, began to move it across the boundary… and one of the man’s pet dingoes came over and stood in front of them, blocking their way. Mighty magic indeed.

So, they’ve now made it out of Australia. Next game will be a session or two of Troika, for which I’ve written a small adventure. And after that, England.

RPG Blog

It’s called Look What the Shoggoth Dragged In

I did end up starting that RPG blog.

I’m planning to post once a month, it’ll be a mixture of mechanics musings, GM advice, reviews, and short adventures. Next month’s post will either be first impressions of Troika, or on fudging dice. I’ll write up my Troika adventure after I finish running it.

Software Engineering

Roleplaying Games