Frank Mitchell

Who else wants narrative mechanics in RPGs?

Beyond the Wall and Other Adventures has three types of tests. There are ability checks, saving throws, and combat rolls. My previous post was about changing the mechanics of ability checks. I wanted to have all three tests use the same mechanic. Roll a twenty sided dice, add bonuses, and compare with a target value.

My reason for wanting unified dice mechanics is that it makes the game less confusing. I got confused while reading the rules. I figured if it confused me, anyone I was playing with was going to get confused as well. Now I’m reading through the rules again. I’m realizing that part of my confusion comes from the language used to ask for tests.

Ability checks, as a test of player skill, use this kind of language.

Player: “I try to jump across the stream.”
Gamemaster: “Roll to check dexterity.”

So rolling the dice is a test to determine something about the player’s skill. Am I skilled enough to jump across the stream or do I fall in the water? It’s a test every player that wants to jump the stream must pass on their own. We can’t use a group skill check, because my stream jumping skill won’t help you.

But ability checks can also be a test to determine something about the environment. Those ability checks use this kind of language.

Player: “I try to jump across the stream.”
Gamemaster: “Roll to see how slippery the bank is.”

This opens up interesting possibilities. Say I’ve got a dexterity of 16 and I roll an 18. The stream bank is more slippery than my dexterity can overcome, so I land in the water. Other players can decide they’re going to jump over a different part of the stream. They make their own ability checks, and hopefully find a less slippery spot. Of if I roll a 7, the other players may decide to follow me, since the bank isn’t very slippery there.

This feels like a collaboration. Everyone’s rolling to figure stuff out about the world we’re playing in. It’s also not going to break the game, since I’m not changing how ability checks are used or how they map to bonuses. Rolling under for ability checks now feels like a natural thing. I know what my character’s ability score is and what they can do. I’m rolling for the unknown, to see what the environment does.


Saving throws have a similar linguistic duality to ability checks. Suppose a mage casts entanglement on some vines near the player. As a test of player skill, the saving throw for that spell uses this kind of language.

Player: “I try to escape the vines. ”
Gamemaster: “Roll to save versus spell.”

But saving throws can also be a test to determine something about the environment. The entanglement saving throw could use this kind of language instead.

Player: “I try to escape the vines.”
Gmaemaster: “Roll to see how quickly the vines grow.”

If the player is a level 2 rouge, their save versus spell is 15. So they try to roll greater than or equal to 15 on a twenty side dice. If they succeed, the vines grow slowly and they may be able to escape. But if they fail, the vines grow quickly and they become entangled.

I like this idea of ability checks and saving throws fleshing out details about the world. It’d be nice to keep the mechanics consistent with the language. If I’m more resistant to spells, my save versus spell value should be higher. Fortunately, that’s an easy thing to change by rewriting the saving throw tables for each class.

When rolling a twenty sided dice, there are six rolls that succeed with a save versus spell of 15. So rolling under on a 6 is equivalent to rolling over on a 15. Here’s the complete conversion table from 1 to 20.

Roll Over Roll Under
120
219
318
417
516
615
714
813
912
1011
1110
129
138
147
156
165
174
183
192
201

I did those conversions for the warrior, rogue, and mage, and came up with new tables. My copy of Beyond the Wall shows the rogue’s polymorph save going from 12 to 13 between levels 2 and 3. I assume that’s a misprint, so I’ve corrected it in the table below.

The Warrior

Level Poison Breath Weapon Polymorph Spell Magic Item
174645
274645
385776
485776
5107998
6107998
711810109
811810109
91310121211
101310121211

The Rogue

Level Poison Breath Weapon Polymorph Spell Magic Item
185867
285867
385967
485967
5961089
6961089
7961089
8961089
9107121011
10107121011

The Mage

Level Poison Breath Weapon Polymorph Spell Magic Item
1768910
2768910
3768910
4768910
5768910
688101112
788101112
888101112
988101112
1088101112

Projects

Bowling pins and the pencil from Spare Me on a wood background.Spare Me is a game about bowling, a fun way to learn math, and a love letter to the world’s second best solitaire card game. It won 9th place in the mobile category for the 2014 js13kGames competition.

The copter from Hard Vacuum: Recon flys over a field of ice.Hard Vacuum: Recon pits your memory skills against the wasteland of a frozen planet in an iPhone game for the 2013 js13kGames competition.

Prolix’s icon spells “lightheartedness”Prolix is a word search game for the iPhone and iPod touch which lets you tweet your scores so your friends can play with you.