Believable Weather for Forbidden Lands

Based on Swedish weather data

Apr 18, 2024

This is a weather system for the tabletop roleplaying game Forbidden Lands. It’s based on meteorological data from southern Sweden. The goal of the system is to feel believable and be easy to use. It decides three aspects in one roll of three D6:

• How cloudy and rainy it is.
• How warm or cold it is.
• For how long the weather lasts.

Using the System

1. Roll a D66 (explained below).
2. Pick the row in the table with that number, that’s your weather.
3. Calculate TEMPERATURE.
   • Start with the base TEMPERATURE for the current month of the year, from the Seasonal TEMPERATURE table.
   • Add the Temp difference from your row in the weather table.
   • Subtract one TEMPERATURE if it’s dark according to the “Light & Darkness” table on page 147 in the player’s handbook.
4. Roll another D6 to determine how many Quarter Days the weather lasts.

A “D66” is when you roll two D6 with one being the ones place, and the other being the tens place. So if you roll a 2 and a 4, you have 24. This works best with two different colored dice to make it easier to distinguish between them.

Gameplay Effects

• Sky affects LEAD THE WAY
  • Clear: +1
  • Rain: -1
  • Deluge: -2
• Wind affects MAKE CAMP
  • Calm: +1
  • Gale: -1
  • Storm: -2

If TEMPERATURE is 5, each HIKING player character must succeed with an ENDURANCE roll every Quarter Day or become THIRSTY.

If TEMPERATURE is 1, all player characters who are not in a camp must succeed with an ENDURANCE roll every Quarter Day or become COLD.

On 65 & 66: For each Quarter Day, all player characters must succeed with an ENDURANCE roll to keep moving. On 66: modify the roll by -2.

Tips

• In the instructions above I split the duration roll into a separate roll to make it easier to explain. Roll all three D6 at once to make it faster.
• Keep the rolled dice for future reference.
• Roll for the next weather early and save those dice too, then you can hint to the players what’s coming next.
• Make it feel more natural by letting the weather sometimes change while the players are active, not just between quarter days.
• When you end a session, note down the numbers on the three D6 for the next session.

Thank You For Reading

If you want to learn how I made the system, read this blog post.