I had an unexpectedly productive bit of campaign development last weekend. I was tinkering with the MapGen2 tool, and thought about creating a quick little Chimera setting. Then I thought maybe I should add some random encounters to that map. And then, having grown tired of typing on my computer, I grabbed a pencil, notebook paper, a roster of wilderness beasties from an long-done campaign, and I headed to the kitchen counter to bang out some custom encounter tables.
Which I hadn't done in a long, long time. Years, really, I think. Custom encounter tables, I'm saying. Not someone else's tables for someone else's setting. And with a pencil. Colour me 1986—a pencil!
Anyway, it was an oddly satisfying exercise rife (it turns out) with lessons for the Busy GM. So let's call January "Make Your Own Island Month," and I'll kick it off with some basics.
Getting Your Island
This is a bit of a side-trek, but it's the easy part.
Go to the MapGen2 Tool and create an island. Play with the random seed and cycle through a few until you find something you like. For scaling purposes, I'm planning to put this onto a Regional Hex template, so the end result will be a square 125 miles to a side (15,625 square miles).
I like the "2D slopes" view for being pretty, the "Biomes" view for better terrain definition, and the "Polygons" view for reasons I cannot yet explain (the irregular hexes might have unanticipated use). Anyway, capture the image, via screenshot or Snagit or whatever you use and save it as a PNG.
I got clever and popped it into a CC3 version of the Regional Hex template (shown at right—as always, click to embiggen). You could do the same with the Hexographer version of the template—just select the PNG as your "Import" map and the Regional Hex template as your "Load" map. 
If all you had was the PDF version of the template, you could save the PDF as a PNG, then load up the MapGen2 PNG in Photoshop or even Fractal Mapper, adding the template as a semi-transparent layer. But that's going to be more work, and I haven't the skills, so more talented cartographers than I will have to weigh in on that one.
Now that you have your map done, we can get back to the encounter tables. You'll need to give your map about 2-3 Earth minutes of thought: basically, what's the climate and what's going on there (i.e., why would PCs be there?). Here's a quick table to get you thinking:
What's Going On?
Rumoured home of lost civilisation
Fastness of an unworldly ruler
Untamed wilderness ripe for settlement
Lousy with riches to be exploited
Primitive peoples ripe for conquest
In this case, I've named the place the Minocra, which is a sub-tropical island that the mainland kingdom wishes to colonise. But there will be opposing natives, dangerous creatures, and (natch) some ruins to explore.
Alright, this is what started off this little jaunt: encounters.
Let's begin with an important fact: the only good encounter table is the one you create yourself, for your campaign, with your gaming group in mind. While most rulebooks include "stock" encounter tables, they tend to include every monster in the rules, even the ones unsuitable for a random encounter in your setting (because they're too rare and powerful to show up randomly, or because they don't live in your setting, or because, like the flumph of old, they're stupid and useless).
Custom tables, on the other hand, omit things your campaign doesn't have and let you dictate the frequency of what's left (which turns out to be important because there are few things worse than relying on a random roll for inspiration only to get a result you don't like).
I recommend a series of hierarchical tables and sub-tables (more on exactly how next instalment). This structure is inspired by the Rules Cyclopedia, which provides a single table for each terrain type (forest, desert, mountain, etc.) with a group of high-level, broadly defined encounter types. The detail of these types is contained within various sub-tables. While the Rules Cyclopedia goes only two levels deep, the potential exists for infinite nesting, which means you can get as detailed as you like.
Starting with the ultra-basic "details" I've established about Minocra, we know that the island is in a sub-tropical climate. Looking at the map, we can pick out some terrain features. Let's start with jungle and, using the guidelines above, we might customise a two-level structure like this:
Sub-tropical Jungle Encounters
Blood on the trail
Animal snare set by savages
Burial cairn (d6: 1-4 ruined and collapsed; 5-6 untouched)
In this case, you'd roll 1d4 to determine encounter type, then a second 1d4 to identify the actual encounter.
There some improvements we can make to the actual table (tune in next week), but for now, I just want to illustrate the whole table/sub-table bit, because it's a surprisingly powerful tool.
The goal (well, one of the goals) of this exercise is to get comfortable making custom encounter tables. These help define your campaign better than anything you'll find in a rulebook. Which is not to say that you can't use whatever random tables the rulebook offers, but do so as a starting point—picking and choosing the things you want in your setting, adjusting the odds of those things appearing, and essentially discarding the rest.
Doing so also helps stimulate the imagination—as you craft your tables, you'll sub-consciously start to create trends and define distinct areas of the setting. By placing certain encounters in different places, you're forced to think about who's in your setting and what they're doing there. Naturally, you'll then need to figure out the "why," which of course comes in handy when you're planning adventures or even running a hex crawl for your group.
Finally, all this gives you an opportunity to create connections between encounters that might otherwise be ignored, and these can form adventure hooks, or just good setting detail.
Next week, I'll take a stab at a quick-and-dirty encounter table format that should have you populating your setting in record time.
These templates are available for download on the Hex Templates page.