River Encounter Generator, Part 1

This is the first of two tables for a river encounter generator. It is tailored for a jungle environment, but can be easily modified for forest. Once the series is complete, you will be able to easily create a quick river encounter for a 5e adventure. 

River Encounter:

These tables are intended to assist in creating a jungle river environment. Players will need to obtain a vessel; either a keelboat that will require a captain (a player with the sailor background or proficiency in vessels (water) or hire a captain; a minimum of four crew will be needed for larger keelboats which can be manned by the party or hired) or a suitably sized rowboat(s). The stats for these boats are outlined in the DMG (p. 119), but they can be reskinned for whatever appropriate setting.

Distance between shores is typically 25-75 yards across, but can be wider or narrower. The exceptions are lake, overgrown and braided sections. The banks are thick with jungle undergrowth and heavily shadowed by the dense canopy, not to mention the occasional ancient ruins overgrown with vegetation.

River Section:

Roll a 1d12 once per day (unless otherwise noted or needed) to determine what part of the river the party will attempt. Skill checks are needed to navigate the vessel successfully. Its assumed that all passengers have a rudimentary idea of how to navigate the vessel. Proficiency with water vessels is ideal, but a successful DEX or INT check may be enough (although, the DM may want to apply a disadvantage if the player attempting the roll doesn't have the proficiency in the skill) If the section takes more than one day to complete, reroll the applicable skill check.

1 – Rapids: (Speed: 8-10 MPH) The waters thrash around and over a rocky riverbed. This is a very dangerous section of the river. Only the most skilled sailors should attempt to navigate this section of the river. (DEX DC20 or Proficiency Vessel (water) DC 17, 4d10 Damage on failed skill check, automatic full damage if the skill roll is 1; full attention must be given to navigating a rapids, anyone attempting to navigate can do nothing else, if no one navigates the boat automatically hits a rock for damage; if someone who is not navigating attempts an action, they incur a disadvantage due to violent nature of the situation)

2-3 – Calm, but fast moving current with high banks: (Speed: 6 MPH) This section of the river move smoothly, but fast. Very little effort is needed to move the boat downstream, some skill is required to keep the boat facing in the right direction. Landing the boat is difficult due to fast current and the high banks. (DEX DC15 or Proficiency Vessel (water) DC12 to keep straight or land on a low part of the bank; if the vessel begins to spin in the current, then any action taken receives a disadvantage;  if landing is attempted and skill check fails then 2d10 damage for hitting the bank)

3-4 – Overgrown, tight channel: (Speed: 1 MPH) This area is shallow and thick with the encroaching jungle. Polling, careful paddling or even walking the boat through the shallowest areas may be the only way to navigate. Masts need to be lowered to clear the jungle canopy that reaches over the river. There are no close banks as the water reaches through the jungle in what may be a flood plain or wetland, although the jungle is usually too thick navigate outside of the main river. (STR DC 10 if walking the boat is attempted)

5 – Lake: (Speed: 3-4 MPH with sails) or (2 MPH with oars and rested crew) The river opens into a large body of water. It is typically deeper in the middle compared to the shore. A slight current continues between the two mouths of the river (or predominate mouths, if there are more than two). Strong weather can make the lake treacherous. (DEX DC 8 or Proficiency Vessel (water) DC 5 to navigate by rowing, INT DC 10 to navigate by sail or Proficiency Vessel (water) DC 7; if skill check fails by more than five, no distance made; if less than five, half of the distance)

5-9 – Windless, slow moving current with meandering channel: (Speed: 3MPH with oars) The river moves slowly around large bends and turns. The jungle lines the banks which slope gently and are easy to land the vessel. The wind is blocked by the thick jungle and sails can’t be used. (DEX DC 8 or Proficiency Vessel (water) DC 5 to navigate by rowing; if skill check fails, the vessel makes only 1 MPH and spins slowly in the current)

10 – Waterfall: The water falls over a severely sloped rocky outcrop. Navigation is impossible. The vessel will need portage around the obstacle. This could be an intensive maneuver requiring more than one day to complete depending on the size of the vessel. The waterfall is not so high that the portage around is suppose to be impossible. If the vessel attempts to go over the falls, the boat is automatically destroyed and any contents (characters, gear or otherwise) are swept downstream or destroyed.

11 – Underground: (Speed: 5 MPH) The river meets a large cliff face. The current increases as the water is forced into the mouth of a cave. The vessel is swept into the cave. The cave turns and twists disorienting the crew. All natural light is quickly lost. Unless the crew has some way of seeing in the dark, navigation is impossible and the vessel is at the mercy of the current until they exit the tunnel. (DEX DC 13 or Proficiency Vessel (water) DC 10 to keep straight or land on a dry area of the cave; if landing is attempted and the check fails, then 2d10 damage; if no one attempts to navigate (by lighting a torch, darkvision or magic to see) and the boat is left to the current, the vessel has a 75% chance of hitting the side of the cave and receiving 2d10 damage)

12 – Braided: (Speed: 3 MPH with oar or 4 MPH with sail) The river splits into many smaller canals that wind back to each other or wander away from the main river. The water moves around long, thin islands and hammocks. The distance between shores is greatly reduced. It is difficult to determine between the main river bank and islands. Once the crew decides on which canal to take, a reroll of environments may be appropriate.  The DM will decide whether or not the crew’s choice of canals leads to the intended destination, back to the original river or somewhere completely new.  (DEX DC 8 or Proficiency Vessel (water) DC 5 to navigate by rowing; DC 10 (or DC 7 with proficiency) to navigate by sails (if there is wind);  if skill check fails, the vessel makes only 1 MPH and spins in the current)