The Survivability Onion and You

So if you haven’t seen the survivability onion, here it is!

Its a way of analyzing the layers of defense around you when you’re in an armored vehicle. And I thought that we could apply this to ttrpg combat so we can understand where various parts of combat game design lay.

Layer 1: Don’t be there

The best way to avoid serious injury or death is to simply not be anywhere near goblins, skeletons, dragons, trolls, or anything else that might want to rip your face off and grind your bones into dust. However adventures are quite foolish creatures and will almost certainly go places they probably shouldn’t.

However should the players deem it necessary to engage in the foolishness that is adventure, they should at least have the tools and wherewithal to research, scout or otherwise gather information on where they’re going.

Things such as hex-maps, point-crawl maps, rumors and seeded adventures are all tools that are designed to reduce the cognitive overhead on the GM while also providing the players with opportunity to make informed decisions.

If you’re game doesn’t give players the opportunity to have agency in the story, then this layer of the onion doesn’t exist in your game.

Layers 2 & 3: Don’t be detected and don’t be identified

So I’m gonna lump these 2 together because often the end result is the same and in many scenarios if you choose one layer, you forgo the other layer. (Its very rare for a sneaking thief caught snooping around be able to quickly come up with an innocent explanation)

To quickly clarify, layer 2 means the enemy does not know you exist (stealth), and layer 3 means the enemy does not know you are a threat (social stealth).

I’m lumping these two together because I think that they both rely on a few things to be relevant. I think that in order for players to engage in stealth and negotiations, a game needs systems to make these interactions fun and rewarding. Players are motivated by 2 things: treasure and XP. How XP is awarded will determine what behaviors you get from your players. If XP is given by defeating enemies in combat, then players will probably not engage with these layers of the onion much, unless it is to give themselves an advantage in combat.

Layer 4: Don’t get targeted

This is the forgotten middle child of the security onion. The enemy knows you exist and knows your a threat. Hostilities have begun. But the enemy isn’t attacking. Why? It might be because they are blinded, befuddled, bound, or burdened. You might be simply out of reach, or they might have other priorities.

This is the layer where a lot of character abilities and player creativity can really shine.

Layer 5: Don’t get hit

This is where most combat systems live. This is where edge meets edge. The Black-Knight is swinging his fell blade at you, do you get hit? Do you block? Parry and repost? Dodge? Cast a quick spell to turn yourself into smoke?

Things such as saving throws, AC and evasion live here. Now, depending on how you conceptualize HP, it also lives here. If you think of HP as a measure of heroism or plot armor, and the ability to do what it takes to stay in the fight… then when you lose HP you’re not actually getting hit at all.

A lot of systems (Draw Steel) remove rolling to hit all together, because a negative result: “you miss” can be a little boring. But I think an alternative would be to make defending a bit more reactive. That way you can have some player choice and enemy characterization in the *way* one defends themselves.

Layer 6: Don’t get injured

I changed this layer because “don’t be penetrated” is very specific to armored vehicles.

This is the layer where HP, armor systems, saving throws, damage types and damage resistances/weaknesses etc. live.

So this layer is somewhat difficult to differentiate from the previous layer, but I think its important to pull these apart because not every hit actually matters. If your character has all the same abilities and options from before they were hit, and all that changed was a number of hit points… then did that hit really matter? Sometimes spells, abilities or the rules of getting injured will apply conditions or penalties which degrade your character’s effectiveness in combat.

I think that splitting these layers can make build variety feel distinct. A nimble light armored rogue is going to be hard to hit but vulnerable, while a heavily armored knight will be easy to hit but hard to injure. Giving the two builds different relationships to the different layers of defense. And if the system you’re using has some kind of action economy cost to reactive defense, then a heavily armored character has the luxury to commit more to proactive offense, while the rogue might be burning action points just to keep the claws and teeth of their cloaks.

However, splitting these layers up incurs a bookkeeping cost on combat: Yes, you hit, now we have to pull out a whole new system just to calculate the impact.

Layer 7: Don’t Die

The last and most precious layer of the survivability onion is to hold on for dear life as your lying on the floor bleeding out.

This is where your design can define how punishing it is: Does this layer even exist or do you just die when you hit 0 HP? How long can you last on the ground waiting for your friends to come render medical attention? If they did get to you in time, what’s does recovering from that look like: A good night’s sleep or 9 months bed rest? Are you permanently scarred or disabled from the experience?