gemini://idiomdrottning.org/attack-value

It’s for when you’re using the common house rule (it’s been seen, among other places, in the 3e Unearthed Arcana book) that the players roll to attack monsters and roll to defend from monsters, and the monsters have static values for defense and attack. There’s still the same amount of rolling total, so you don’t change any outcomes, only the feel of the game.

The rule as published had the wrong math, they subtracted on the wrong half of the equation, so here are the numbers we use:

Monsters’ attack value is their hit bonus plus ten. For most monsters, that just means reading the + as a 1.

Player character’s modifier for defense rolls is their AC minus twelve. Note that down instead of noting your AC down. So unarmored means -2.

Spell casting players roll “saving throw checks” which is the exact same modifier as their normal spell attack, except you can’t crit. So you only need to keep track of one number there, no need to know a “save DC”. (Spellcasting monsters use save DC as normal.)

For opposed rolls player-vs-player, have both players roll when fighting. Defender wins ties. In PvP spellcasting, the attacker always has an 8 so only the defender rolls. In PvM opposed rolls for ability checks or what not (hello grappling) I’ve often had monster just get a standard 10, but that does change the probs compared to both sides rolling so it’s often better to just do that.

We’ve used this for many years, we started using it gradually (players would have both a normal AC and a “defense roll” listed) but then went over to using it all the time. Even now, eight years of using it all the time, I don’t know what I think about it.

Why 14 and 12? That's just what the numbers need to be to get the exact same probabilities as 5e. Knave gets the probabilities right with an even ten by changing the “the roller beats ties” semantics familiar from D&D. I didn't wanna do that, and by the time Knave came out I had been using these numbers for years already.

It makes them handling the game items (dice and numbers) all the time at the expense of the mood and tension of the diegesis. Sometimes I wonder if the other way around wouldn’t‘ve been better. The players only focused on describing their actions. I even wrote a ruleset based on that idea.

Being able to defend feels great. Fans of RuneQuest, GURPS, and Hackmaster knows what I’m talking about. But they bog things down with extra rolls while this keeps things fast and easy with one roll per chop.

Players are more aware about what’s incoming and what’s at stake. And they roll so the DM can’t cheat. I always say the attack value so they know what they need to roll against.

It’s the best implementation of a fumble ever. A 1 on your defense check means the enemy critted. Unlike some fumbling rules, you’re not getting punished for having many attacks (the opposite is true, enemies get rewarded for having many attacks). I am ordinarily pretty strict at always describing things in terms of competence—you “missing” is not “lol three feet to the left of foe”, it’s just that the enemy is that good at parrying—but here is a rare chance for you to bring back that slippery mud, that loose grip, the chance of leaving a fatal opening when it counted.

It really does offload the DM. A lot. Having one player roll the defense check (and HP cost, if you’re rolling for damage) while you’re talking to another player can be great and cut down on downtime.

We use it in combination with Oh, Injury! and an interwoven initiative system and it’s been synergic with them. They swing at you, you try to parry, but their attack was a feint (you didn’t make the defense check), so you exert yourself (you pay hp) to twist yourself to the side to dodge their blade, and then you follow up with a swing of your own, and it lands and fells them. It’s pretty great, and all with the same underlying math as D&D, meaning that you have access to hundreds of well-playtested monsters and dungeons.

It goes without saying, but defense checks, just like momentum attacks and the golden opportunity strike from Oh, Injury!, don’t cost any actions in the initiative order. This is great, makes those six seconds a round take really frantic.

Attack value

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