The PCs should come across a river that is flowing too quickly to easily cross on foot, and no bridge or ford in sight. A small rowboat, big enough to hold two people at a time, is sitting on the shore closest to the PCs. Also on the shore with the PCs are a number of ogres equal to that of the party members, who are standing around grumbling and arguing with one another. At the sight of the PCs, they accost them, insisting they need their help to ferry them across the river. They note that they have been stranded here a while, and are growing hungry.
This encounter is based on an old logic puzzle known as the "missionaries and cannibals problem" or "jealous husbands problem" - to boil it down to the essentials, you have to get two parties of equal size across the river, making sure that Party A does not outnumber Party B on either bank of the river at any time.
In this case, the party must transport each ogre to the other side of the river. The boat can hold two people at any time - they can be ogres, PCs, or any combination of the two. However, the ogres are hungry enough to make a bid for the PCs if they think they can get away with it. The ogres are cowards, and they won't try to attack the PCs if there are more PCs present on their bank than ogres. But as soon as they outnumber the PCs on a given bank, they'll attack, ganging up on the PCs so they can kill and eat them.
To make sure this information is available to the players, you may wish to have one of the ogres grab for the outnumbered PC(s) as soon as the boat begins to leave the shore, so that whoever is rowing has a chance to intervene - if the ogres see them change course, they'll immediately drop what they're doing. In any case, the party will either have to take multiple trips to get all ogres and PCs on the other side of the river, or prepare for a fight.
According to Wikipedia, the missionaries and cannibals problem can be solved in a minimum of 11 moves if there are three missionaries and three cannibals (or husbands and wives, brothers and sisters, masters and valets...you get the idea). In order to add urgency to this encounter, you could have the tides slightly rise after each move - the PCs must solve the puzzle in, say, 20-30 moves (to give them leeway to make mistakes) before the tides become too high to safely cross the river. If this happens, they might be swept away, potentially requiring them to make some rolls to avoid being tossed overboard, or perhaps they'd be washed away to a new location. In my campaign, I had three party members and three ogres. If you have a larger party, you'll need to increase the number of alloted moves.
In my campaign, one of the ogres had a broken arm, preventing him from rowing the boat. This would explain why the ogres couldn't row themselves across, and forces the PCs to man the boat at least once. However, my players used this to surmise that the ogre with the broken arm wouldn't be able to fight them either, and that he wouldn't count toward the number of ogres outnumbering the party since he couldn't pose a threat. This made the puzzle significantly easier, but it was logic I couldn't argue with, so I let them have it.
Since I was using this puzzle in a dungeon, I had a door open once all the PCs and ogres were on the same side of the river. You could have this be operated by a pressure plate that will only open under the combined weight of all PCs and ogres standing on it (note that creatures would not need to be alive in order to meet the required weight). Or you could have a passage or treasure located on a higher ledge that the PCs can only access by climbing on the ogres' shoulders.
No comments:
Post a Comment