Craft killer climbs

Bring mountaineering to your game.

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Last week I threw some topography onto a hexmap. A reminder of last week’s map:

Image Credit: Me

There’s some other rules I want to throw in the stew pot. These can be used outside the topographical map too.

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Altitude

Let’s call anything around sea level “altitude 0”. When players ascend or descend, add or substract from the current altitude, respectively. Dotted lines are 1 point of altitude, full lines are 2 points. Note: We won’t be doing negative altitudes here so anything below level 0, stays as level 0.

You can note this altitude on your hexmap, or even in a hexcode. You could take Chris McDowall’s compact approach to hexcodes and add an altitude measure.

Each point assigned for an altitude level change represents around 0.5km, around a 1/3 of a mile for Imperial users (we’ll use this later for a rough judgement).

Of course, your average mountain is not a flat ledge, there are inclines, flat sections and declines. The altitude rating gives us the maximum height of the terrain within the hex region.

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Climbing checks

Last week we used two kinds of lines, dashed for shallow gradients, solid for steep.

Steep lines require a check to cross. You can use any kind of climbing check/system you like, though of course I have my own approach.

I modify a climbing check by the altitude value. I like a d20 roll, where you need to roll above the target altitude to climb without incident. If you’re ascending from 0 to 1, don’t roll a one. From 4 to 5, don’t roll below a 6. From 3 to 2, don’t roll below a 3.

I like rewarding players for preparing. For example, if they take a watch to observe the route (provided visability allows), they roll the check with advantage. If the weather presents low visibility (we’ll talk about this soon), checks are at a disadvantage.

Make a table of climbing incidents for failed checks. Example:

Climbing Incidents (d6):

1: Fall d100ft. Use fall damage in whatever game system you are using.

2: Slip and sprain an ankle. Speed halved until healed.

3: Rock fall. 1d6 bludgeoning damage.

4: Gear slips away from you. Lose an item.

5: Exhaustion. Must rest immediately after completing the climb.

6: Vertigo. One of the party starts to panic.

This gives players risk-based choices: take a route without steep gradients (probably longer), or take the risk and climb.

By the way, if you’re interested in using hexmaps check out our new line of notebooks! You can order them here.

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Altitude Sickness

Many humans start to struggle at altitudes over 2km (equivalent to 4 altitude points), as oxygen deprivation takes its toll. When characters arrive at an altitude of 4 points or above, have them make a relevant physical health check for the first two watches at that altitude.

If they fail, have them roll an effect on an altitude sickness table, like this:

Altitude Sickness (d4):

1: Confusion. Disadvantage on mental checks.

2: Breathless. Speed halved.

3: Weakness. Disadvantage on physical checks.

4: Sick. Take 1d4 damage from vomitting every watch.

This effect lasts until they shake the altitude sickness. They keep rolling on every watch until they succeed or descend to a safe altitude. These effects stack with subsequent failures, but you can waive that if you don’t want to be so harsh. ~I myself enjoy inflicting multiple layers of suffering, like a tasty cake - see my approach to cave flooding~

When the characters ascend further, they continue to make checks for the next altitude level. It’s worth noting that at altitudes of 10 points (5km plus), most people require supplemental oxygen to avoid lethal hypoxia.

Weather

Make a weather table that suits the biome, with the harsh results assigned to higher numbers. A d20 table works well for this.

Roll once per day in lowlands (altitude 0), but once per watch (morning, afternoon, evening, night) in highlands (anything above 0) to simulate the changeability of weather at high altitude. See the example below, where compromised visibility means disadvantage on climbing checks:

Weather (d20):

1-5: Clear.

6-10: Overcast.

11-15: Rain.

16-18: Fog/snow (low visibility).

19-20: Storm/blizzard/gale (low visibility, 1 damage per hour if unsheltered).

You could rule that cold weather clothing reduces damage for a watch. Build in whatever effects fit the weather you like.

You could also use a more advanced weather pattern generation tool, like this.

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Note on hexmap scale

We’re using a 6 mile per hex scale in my map above. Realistically, mountains are not typically that wide, as pointed out by r/osr and other rpg subreddits. Decreasing the scale of the hexes will work if you want something more realistic than my fantasy mega mountains. It’s worth noting that by using 6 mile scaled hexes, we stick to the scales used in a stack of games, from Forbidden Lands to Traveller.

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Wrap up

Now you’ve got a toolkit (in addition to the hex topography guide) to make alpline exploration the gruelling, unforgiving death trap it should be! Go forth and make mountains murderous.

If you like this article, please like and share! Commenting helps out MurkMail a lot and I love chatting with you folks. What do you think of this approach to mountaineering in games? Come tell me on the discord.

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Recommendations

Sale: DriveThruRPG has a map-focused sale on! I’ve grabbed the detailed map of Duskwall (the Blades in the Dark setting) for an upcoming project of mine.

YouTube: Dave Thaumavore talks about his experience of running more open adventures, specifically in Forbidden Lands. Dave gets across the freedom he experienced as a GM by moving towards more open adventures, which is nice to re-experience if you’ve already made the move to more open adventures yourslef!