How do you give your campaign realistic weather without overloading the GM with Admin tasks?
Weather is never an easy subject. On its face, it looks simple, but let’s consider the real world that any game system would have to model. Weather is driven by Chaos Mathematics, which means that tiny changes can cascade into monumental consequences. A butterfly flaps its wings somewhere at the wrong place and time and you get different weather 2000 miles away and five days later. So the reality is difficult to reduce to a simple simulation, which is what you need for an RPG.
Of course, we’re not necessarily all that interested in accurately modelling real-world physics. It’s a game, and simulation verisimilitude can and should be sacrificed in the interests of playability as necessary. But even then, there are other problems that make weather a difficult subject to handle well.
Weather is a non-static system, where one day’s weather influences, but does not dictate, what happens tomorrow. That means keeping track of day-to-day events and ensuring that the trend, over many game seasons, reflects the climate that has been deemed by the GM to be appropriate to the geography in question, while still providing the degree of randomness that’s necessary to making it feel real.
So, with that in mind, here is a quick review of the different solutions I have used over the years, with their pros and cons:
1982: My First Weather System
One of the earliest House rules I introduced into the first campaigns I GM’d was a weather system. Each geographic region would be assigned a climatic model that specified seasonal baselines for temperature mean (both day and night), temperature variability, rainfall likelyhood, rainfall intensity, rainfall duration, and so on. A couple of die rolls then gave a random value within the indicated range of statistically likely results, with a slight chance of an extreme weather result. What made the system a little different to others that I had seen in The Dragon and in other campaigns and rules systems was that each die roll provided a modifier to the results of other die rolls relating to that particular day’s weather, and another to the rolls for tomorrow’s weather, and another to the weather for the day after, and one to the season overall. Some of the these modifiers acted to exaggerate the more extreme results in severity and likelyhood, some to bring it back towards the climatic baseline, and some introduced long-term biases. There was even a threshold limit that would indicate a climatic shift for the geographic region.
This system, with two competing feedback loops pushing weather toward extremes and toward conformity, respectively, worked a treat as a weather simulation system, but it was a lot of bookkeeping and a lot of work to maintain. And it wasn’t properly documented. So when there was a critical failure of the real-world weather around me, and the rules were reduced to soggy woodpulp, it was abandoned.
What happened? Well, it’s not really relevant, but I’m sure you won’t let me out of the building without an explanation so, in brief: I was unemployed at the time, and could not afford public transport both to and from gaming. One way, yes, but not the round trip. So I used to walk the 16km home each Saturday night, with a heavy backpack of rulebooks and notes, rain or shine, hot or cold. It took me between 4 and 6½ hours depending on conditions and load. So, one summer’s night, I got caught out in the open by a seasonal but unexpected storm which ripped my umbrella to shreds and thoroughly soaked anything in my non-waterproof backpack that wasn’t protected. The weather tables bore the brunt of it, but protected everything else, so I couldn’t (and can’t) complain too much.
1983-2002: The Real World
For the next many-some years I largely ignored the question, or took whatever was happening outside the window, seasonally adjusted. A cold, wet, day in summer became a cold, wet day (or heavy snow day, if appropriate) in winter, as necessary. A simple solution, but one that my players quickly cottoned onto and started to take advantage of.
So I started inverting the pattern – a cold, wet day became a mild, dry day in winter. That took a little while longer for them to figure out, because sometimes I was lazy and didn’t swap things around. But within a few months, they could get it right 90% of the time.
So then I started using tomorrow’s forecast as today’s weather. That worked for 2 years. Then I started inverting tomorrow’s forecast – another year, but by now it had become a game-within-a-game to them, a challenge to get them warmed up for game time.
When they started getting too good at that, my TORG campaign was just getting underway. I decided to start using the weather as it was on the day I first drafted the scenario as a basis – whether it was a day, a week, a month, or six months in the past.
These techniques all had the additional advantage that I didn’t have to tie the daily weather to a specific season, just document conditions relative to whatever I was expecting.
That worked for more than 5 years, until that campaign came to an end, and I found that when starting a new campaign, the system didn’t confer enough variation from day to day, because so many scenarios when a campaign are starting out are gestated simultaneously, or close to it. So it was back to the drawing board, and a search for a new solution.
2003: Weathergen 2.1
In 2003, when I started running my original Fumanor Campaign, I came across an online program called Weathergen. You specified the climate and the season and it generated a full month’s weather for you as a web page. It was not as sophisticated as the customised solution that I had developed years earlier, but it was a lot less work, and I used it exclusively for that campaign. I would still be using to this day if it were still available, but it’s not. When I went to generate weather for the opening session of the One Faith Fumanor campaign, I got a 404 – website not found.
2007: The Quest Begins
So I started searching all over the place for alternatives. There are weather generation software packages out there – a Google search for “+RPG +Weather +Generator” finds 32,800 results – and I’ve downloaded a heap of them to trial. None of the ones that I’ve tried have quite satisfied me, but that hasn’t bothered me, because I’ve found a new solution based on modern technology.
2008-9: The Internet Beckons
With the advent and modern ubiquity of the internet, many countries have official websites devoted to their bureaus and departments of meteorology. These not only provide current forecasts, they also frequently have historical information. Supplementing these are the many newspapers who have online archives, which sometimes include weather forecasts. So these days, I draw up a shortlist of “terrestrial equivalent” locations and use the appropriate forecasts for the season. It can require a little planning ahead – if, for example, I know that the PCs are about to be in an Athens-like climate in summer, and it’s currently winter there, then I really need the forecasts from six months ago; there are only two ways to get those, either through an archive of some sort, or by collecting the information that I need six months in advance.
Derailing The Plot Train
That need obviously tends to encourage plot trains, if the GM doesn’t take precautions. To guard against that, I try to look not at where I expect the PCs to be, but at a subset of places they might be and prepare accordingly. After all, if I gather information that I turn out not to need, I can always put it in a drawer until I DO need it. I also like to declare a secondary source in the other hemisphere if I can find one that can be used if I need something unexpected at short notice. If I have to, I can take a semi-appropriate forecast and tweak it to my needs – I might take temperatures from New York and rainfall from Sydney to simulate an area that is bone-chillingly cold in winter but receives only widely-dispersed heavy snowfalls.
Ultimately, all you need is a starting point for inspiration and the rest can be faked.
You ask a great question, because weather in RPGs is a chronic under-achiever as a game element (pun not intended). I agree with Mike’s advice. Here are a few additional thoughts:
Build Your Weather a Year in Advance
If the location of the story is going to be fairly predictable, then determine your weather a year in advance, or for as long as you think PCs will be in the region. (I once calculated weather for a whole decade because I was GMing a home base campaign.) This not only gives you an answer for every day of the campaign for a long period of time, but it helps you do this bit of campaign planning in one short sitting.
If the location isn’t predictable, you’ll need to create weather on a shorter term basis, or possibly mid-session.
Weather Should Affect Gameplay
Make the weather affect the game. How does it impact the PCs? How does it impact their foes, locations, encounters, and plot points? If you’re going to put thought and effort into generating weather, then put it to use during encounters and situations.
- Weather for pure flavour is great and is a minimum requirement. Use weather as another way to provide detail and description. Yesterday the smithy was where the PCs dropped off gear for repairs. Today it’s a wet and cold place because a chill wind is blowing rain under the awning and into the work area, and wide streams of water flowing off buildings and through the middle of streets makes everyone clutch capes and hoods tightly as they dash between places, leaving no room for identification, much less chatter.
- It also is a good tool for generating hazards and boons. Consider the risks of being cold and wet, the benefit of having the wind at your back, and the boon of clear skies for direction. As a bonus, weather can be dropped anywhere outside and provides temporary dangers to make common routes interesting again.
- Game mechanics for weather effects are good too, for some games, such as D&D. They can reward character building choices (such as outdoor skills). They can also present the group with interesting options. Is heavy rain coming? If so, should they chance the valley to shave a day off travel time, or take the ridge to avoid flooding, landslides, and other dangers?
So, while you’ve requested realistic weather, please do consider in-game consequences your system of choice presents to characters, encounters, adventures, and campaigns.
Use Earth Patterns
Here are some additional resources to add to Mike’s advice on using real-world weather. (By the way Mike, great tip of basing game weather on the weather currently outside.)
- And Issue #156 featured several Earth weather links.
- In Issue #128 a reader suggests using a Farmer’s Almanac for RPG weather, and Google has many options for online Farmer’s Almanacs.
Use Supernatural Weather to Liven Things Up
If your setting permits, be sure to add weird, extreme, supernatural, or magical weather to your calendar. Such weather adds a lot of storytelling potential to campaigns, keeps the players on their toes, and gives you interesting new encounter backdrops.
Random weather Table
Note that Roleplaying Tips reader Rick Heron devised a random weather table for his campaign that you can download and try out.
The Weather Track
To borrow from D&D 4E mechanics for a minute, how about building a weather track? The thing with many weather generators is they do not take into account season or duration. You could easily build weather tracks per season, or even per month, to provide daily patterns that seem realistic to your players.
And duration is a feature often overlooked by generators. One day it’s sunny, the next there’s a storm, the third day is cold, and the fourth is stormy again. The weather feels random because it bounces around so much at the whim.
I’ve lived in Vancouver, BC where the weather arrives and lingers forever, like a relative who can’t take a hint. Last year I noticed Vancouver set a record for over a month of getting rain every day! Whereas my current home, in Edmonton, sees the weather change quickly, and some days hourly.
Using the D&D 4E track system (ala disease and poisons) lets you mimic a weather system approaching and either settling in or clearing out. Instead of a disease, it’s a weather event. Each day, or hour, make a roll to see if the event strengthens, stays the same, or weakens.
Complement the weather track with a random table of possible events, weighted by chance of occuring in any particular month. Don’t forget to add supernatural events. For each day, roll on the table, and if a weather event occurs, switch to the monthly or seasonal weather track.
In addition, for each month in your game calendar, set a default day. This day represents normal temperature, precipitation, wind, sunrise time, and sunset time for that time of year. When a weather event isn’t triggered, or when one clears up and another hasn’t triggered, the weather reverts to the default day for the current month.
If I had to choose one method over anything else, it would be to generate a year’s weather in advance. I would use a generator or do it by hand, but with a forecast in place, you can smooth out any unbelievable anomalies, change mid-game if desired, and re-use for future years (another tip for another day) and future campaigns.
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