Ship Navigation Rules

These are draft rules for dealing with ship-based exploration. They assume a hex grid sized for 1 day increments (roughly 60 miles). They also assume that you're mostly coastal.

Every day, roll for weather (use Weather table) and, if the result isn't "Storm" or "Bad Storm", for events (using the Event table). At specific points during the journey, the DM may have fixed-location, 100% probable events. Those days, still roll for weather, but that modifies the fiction rather than any normal rolling.

Weather

d8 Weather Check

d8 Roll	Result	Mechanics
1	Bad storm	Use storm event, +5 to lookout and navigator storm DCs
2	Regular storm	Use storm event
3-4	Adverse wind or calm	No progress made that day. Fleet sailmaster makes a DC 10 check. Failure means loss of one day progress
5-7	Normal conditions	Normal progress
8	Favorable winds	+1 day progress

Storms

Storms are special weather events that serve as the most common hazard at sea.

Storm Roles

Each ship needs 3 roles filled. If a PC doesn't fill a role, an NPC fills it. Ships with expert crew have NPCs that roll with +4 across the board. Regular crews have +2 across the board, and undisciplined crew roll at +0. These mostly influence storm performance.

Lookout: Makes Wisdom (Perception) checks for hazards during storms. Determines how much warning the helmsman/crew has to react.

Check Result	Outcome
9 or less	No warning. Navigator is at disadvantage.
10-14.	Some warning. No special effect.
15+	Lots of warning. Navigator is at advantage.

Helmsman: Makes either Dexterity (Initiative) checks or Constitution (Athletics) checks to steer the ship during storms. Determines how bad the results could be (modified by crew).

Check Result	Outcome
4-	Critical Damage
5-9	Damage
10-14	Mildly Favorable
15-20	Favorable
21+	Very favorable

d100

d100 result	Critical	Damage	Mildly Favorable	Favorable	Very Favorable
1-20	shipwreck or major ship damage	shipwreck or major ship damage	(20-result)/10 casualties + scattered	scattered from allies	2 lost days
21-50	shipwreck or major ship damage	(50-result)/10 casualties + scattered	scattered from allies	minor damage (2 lost days)	1 lost day
51-75	(100-result)/10 casualties + scattered	scattered from allies	minor damage (2 lost days)	1 lost day	nothing
76-100	(100-result)/10 casualties + scattered	scattered from allies	1 lost day	nothing	1 gained day

Sail Master: Makes Charisma (Persuasion or Intimidation) checks to coordinate the crew during storms. Good results reduce the damage done. If the crew has low morale, roll at disadvantage. If they have high morale, roll at advantage.

CHA check

Result	Outcome
9-	Use rolled result
10-14	Move one d100 row better
15+	Roll 2d100, keep better result.

Events

Events are land, sea, or special. Generally, non-special events may or may not cause the crew to divert, but special events will.

d8

d8 result	Outcome
1-3	Nothing
4-5	Land event
6-7	Sea event
8	Special event