Sunday, September 4, 2011

SoSA the 3rd: The River, Riled

This is post 3 out of 25 in the Cygnus Series of a September of Short Adventures.

This time, the big opponent isn't an NPC or a monster, but the terrain.

I'll leave out the motivation for getting the PCs up into a high-elevation thick forest, surrounded by branches of the big River Dart. But once they're there, at dawn one morning, an exhausted messenger approaches them with urgent news. A PC's beloved friend (maybe an NPC contact back home) has been accused of a heinous crime, and has been railroaded through the system so fast that they will be hanged at sunset today! What to do?
This blog now has a Bacon number of 2.

The PCs are 50 miles from the town, and it would be several days' journey on foot, or on horseback, through the thick forest. The River Dart flows rapidly down to the town, but there are hazards aplenty.

The messenger knows of a tiny fishing village where there may be boats for hire. Of course, there are, but there aren't any guides available, and the only boats are just small rowboats, fit for maybe 2 or 3 people each.

Anyway, the above was merely an excuse to present DMG Appendix R3: Random River Rapids Generation System...

The total length of river to be traversed is 48 miles, divided into 16 three-mile segments. The surrounding land is dense, marshy forest, so it would take roughly 3 hours to traverse a segment on foot (depending on encumbrance of course; portage ain't easy!). The speed of the river determines how fast rowboats will be carried on the current.

Before play, the DM must generate the river network. Plot the 16 segments from left to right. Segment 1 is just a straight stretch of river. For segment 2, roll 1d6:

1-3: straight stretch continues;
4-5: forks into two branches;
6: merges with another branch.

From here on, there may be multiple branches.  Roll the d6 for each of them to see how
each one may fork or merge. (If there's no available branch to merge with, just make one up!) All possible paths from the start to the finish must be 16 segments long. Once the network is mapped out, roll 1d20 for each segment to determine its speed and hazard class:

1-2: Type 1: slow and easy current. Traverse in 1.5 hours. No hazard roll.
3-6: Type 2: Moderate rapids, clear/wide passages. Traverse in 1 hour. 2d6 hazard roll.
7-9: Type 3: High/irregular rapids, a few obstructions in the river. Traverse in 45 minutes. 3d6 hazard roll.
10-12: Type 4: Long, consistent rapids, several big obstructions. Traverse in 30 minutes. 4d6 hazard roll.
13-14: Type 5: Violent rapids, many obstructions and drops. Traverse in 15 minutes. 5d6 hazard roll.
15: All boats blocked by fallen trees or rocks, but water flows through. Need to portage this segment.
16: Big waterfall. Need to portage this segment.
17: Looks like Type 1 when first entering, but is really Type 2.
18: Looks like Type 2 when first entering, but is really Type 3.
19: Looks like Type 2 when first entering, but is really Type 4.
20: Looks like Type 4 when first entering, but is really Type 2.

For results 1-16, the PCs can see what the segment will be when they first enter it. If they have a choice to make at a fork, they can see what both possibilities will hold and choose accordingly. Results 17-20 are for the times when first appearances don't tell the whole story about a segment.

The hazard roll is a "successful boatsmanship" roll. If you use skills, more power to ya, but I'm assuming that each rower in a boat calls out the larger of their STR or DEX. Then for each rower, average together these scores, and round to the nearest whole number, to get that boat's overall rowing ability score. For Type N rapids (N = 2-5), the rowers must roll Nd6 (see above) and roll UNDER that score to successfully navigate the segment. If they fail, they capsize their boat, each rower takes 0-3 hp damage (1d4 minus 1), and they effectively double the traversal time.

One more thing to do for each segment (either in prep or during play): roll a d6, and a result of 1 means a random monster attack occurs. Roll 1d20 roll to determine which type of beastie attacks. Use standard "number appearing."

1-4: Beavers, giant
5-6: Crabs, giant
7-8: Crocodiles (normal)
9-10: Eagles, giant (from sky)
11-13: Otters, giant
14: Roc (from sky)
15-16: Turtle, giant snapping
17-19: Wasps, giant (from sky)
20: Water Weird

That's it.  I hope the above provides good flavor, but there are many other bells and whistles to add. For example, whenever a PCs' boat capsizes, maybe add another "wandering monster" table where the entries are leeches, rot grubs, disease germs, and so on...?

Oh, and the PC's falsely accused friend? That's the seed for a whole 'nother adventure...


  1. Very cool. Simple, but different and probably good fun, and dripping with a sense of the landscape. The last thought on an extra set of creatures is solid too and I'm thinking the same way. I admire your being bold and creating new mechanisms, and these could be applied to any similar river of course, anywhere.

  2. Thanks! Dripping... pun intended? :-)