Wednesday, 29 January 2014

Monitors core mechanics

I have been repeatedly and nonspecifically worried about the core mechanic (d20 roll under Attribute) for Monitors. I have been unsure about how much granularity I think the game needs, and how much it has, and how smoothly it's distributed across the game. I'm concerned about whether my whole initial aim with the project, of making nonlethal damage a viable and interesting alternative is really being addressed. And most recently, I've realised that there is no mechanic at all for directly opposed action in this system, and that really needs addressing somehow.

Entirely unrelated to this last, I have also started thinking about niche specialisation in games, and want to play with that a bit as well. By "niche specialisation", what I mean is, the tendency to pick a small number of things you are very good at, and then only ever really use those abilities. I should clarify that I have no real problem with the former, but am curious about the latter. Would encouraging people to use their less-good abilities improve the game experience in some way? Are there problems of Party Failure getting in the way? What underlies those choices? How does it relate to things like advancement? Is it something I need to care about in my game specifically?

So maybe we should also look at skills in a couple of categories: Quantitative versus Qualitative success (hit that guy vs. translate this document) and Contributive Success versus Party Failure (Search vs. Sneak). But that can probably wait. One thing at a time.

This may be the start of me ripping Monitors to pieces and starting again. I'm really not sure at this stage.

Doing Stuff

So at the moment, the mechanic for Doing Stuff is:

  • You have an Attribute typically from 0-20, although it can be higher
  • Roll d20
  • Apply difficulty modifiers for particularly easy or difficult tasks. Assume "moderately difficult" is the baseline - this is judged independently of the character's skill to avoid ability compounding spirals.
  • Apply situational modifiers if conditions or equipment affect your chances of success.
  • Apply any personal modifiers from character traits and background, such as experience in the police aiding you on attempts to deal with police bureaucracy.
  • A score =< the Attribute is a success.
  • A score =< half the Attribute is a particularly good success. In combat this increases your chance of inflicting damage, effects elsewhere are as deemed appropriate.

I haven't outlined too many modifiers, and mostly left these up to GM discretion. Crunchiness: relatively low.

There are 16 Attributes at present. Three of these are (let's be honest) largely passive and used for defence. I am somewhat uncomfortable with having two distinct categories of Attribute like this, but I may be over-sensitive.

Characters can take two actions per round.


Combat involves an Attribute roll to attack, followed by an Armour roll from the target to avoid damage. Armour can be ignored by weapons with high Penetration. A half-Attribute roll on the attack forces a reroll of any successful Armour roll.

Hard weapons do 1 Wound, and Wounds are typically 1-5 with most enemies in the lower end of the spectrum. There are penalties for mildly and severely wounded creatures.

Soft weapons inflict a Penalty Die sized 1d4-1d12. This is rolled each round, and on a 1 the penalty has elapsed. The penalty inflicts a -5 whenever it would be relevant, as well as any other consequences as deemed appropriate.

At present, hard weapons are effectively binary (with a slight hedge from half-Attribute rolls) while soft weapons inflict a fixed penalty but have a variable duration, providing some degree of non-binariness. This could be tweaked somewhat.

Lingering effects can be incurred through serious injury, including being taken out of action in combat. These last for a number of Ticks, which elapse when either in-game downtime has occurred, or at the end of a "scene".

Combat spells, in several cases, inflict effectively binary effects on targets, missing the whole point of my game. With very little granularity in the system it's not especially clear how to alleviate this.

Opposed rolls

There is no obvious way to handle opposed rolls. What options exist in the current system?

  • Both roll Attribute. There is either a clear victor or a draw. Half-Attribute roll may or may not trump normal success, I'm not sure it matters. Advantages: simple; better chance of success with high Attribute. Disadvantages: not sure the probabilities are a good model of ability discrepancies; absolute ability seems more important than relative ability; attribute 20 can never lose a contest even against a 19; with skills outside the middle range, lots of draws are likely; draws are frequently meaningless in opposed situations.
  • One rolls Attribute, modified by other's Attribute or some fraction thereof. Advantages: allows for relative ability; avoids draws. Disadvantages: introduces variable modifiers to the game; even a slight discrepancy makes roll impossible.
  • One rolls Attribute, modified by difference in Attributes. Advantages: allows for relative ability; avoids draws; weak Attributes suffer badly from discrepancy whereas strong ones can succeed despite considerable discrepancies. Disadvantages: introduces variable modifiers to the game; requires arithmetic.

The third option seems the most promising. It has a couple of drawbacks, though. One is that so far, there are no variable modifiers in the game: modifiers are either +/-2 or +/-5, keeping it relatively simple. It's not a huge issue, but once variable modifiers exist, it makes sense to consider whether they should apply elsewhere. The other is that it requires a bit of calculation and comparison - it also means knowing the target's relevant Attribute score, but I'm not really bothered about giving out that kind of information.

It also seems to me like this increases the level of granularity in the system. It's not a bad thing, it's just a thing.


Penalty Dice II

One alternative that's popped into my head is a change to the injury model, introducing another degree of variation. In this case, a hit from a weapon inflicts a Penalty Die of varying size. The initial penalty equals the maximum on the die. At the end of each round, the character can roll the die; on a 1 it's discarded, otherwise the penalty is reduced by one step.

Alternative: roll the die each round, including on first hit. Unless it's a 1, the result is your penalty for the following round (reroll 1s on the first hit until you get another number). This offers the potential for an injury to suddenly get worse after apparently getting better, which may seem inappropriate. It does mean not having to remember what the initial score was and track it, though.

Either way, Blind and Slow dice apply to activities involving vision and movement/reaction respectively. The other big change is that Wounding could also move over to a Penalty Die. Rather than having injury states based on remaining Wounds, each Wound can take one Wound Die. The total results on the dice determine your current penalty. Once you run out of Wounds, you're out of action. Unlike Blind and Slow dice, Wound dice only get rerolled in special circumstances - you don't heal actual damage in combat, even though you can shake off being dazzled.

This model is nice in some ways, because it adds a lot more variation to Wounding. A disadvantage is the time taken each round to roll dice. Another is that the most logical way to track all this is by putting dice on a character sheet, and that will use quite a few dice of different sizes once multiple characters come into play.

Finally, it still doesn't offer any way to actually win a fight mechanically with soft attacks. It's always possible for the GM to rule that a blinded opponent will yield to threat, but I'm wary of relying on that. I don't want to allow soft attacks to fill a Wound box, because then you'll quickly hit a situation where soft attacks are just a more effective way to fight people all round (they'll tend to meet lower defences). The only possibility that immediately presents itself is a surrender/finishing blow mechanic, where soft dice might count alongside Wounds towards these mechanics.

Roll and add

Next option: forget this niche roll-under lark. It's more suited to a game with minimal modifiers, few mechanics (at least, few mechanics in that area of gameplay) and a generally simple approach to resolution. Turn to the mainstream, and add modifiers to a roll against a target number.

This scheme offers an immediate and easy way to gauge how well you did, to compare that achievement with anyone else (allowing opposed tests) and readily absorbs any modifiers you care to throw at it.

A disadvantage is you need to have a target number for everything, be it fixed or calculated. This kind of system seems like it increases the crunch level of the game (and, incidentally, makes it increasingly like Dungeons & Lizards In Space). You need a starting difficulty for everything, and it will change how Attributes work entirely. Logically, I should set a Difficulty of 20 for tasks to get the equivalent balance of success (if I care about that). It does feel slightly less intuitive, somehow, than rolling under a fixed number.

I'm also not sure how Degrees of Success would translate into effects in the game, particularly given my combat system. One simple option would be for combat DoS to modify Armour rolls, although this would naturally reduce the value of Penetration, particularly to characters with high combat Attributes. If I did switch to Penalty Dice II, DoS could adjust the number on Wound Dice.


I already have a dicepool mechanic in the shape of Heat Points. The Attributes could translate reasonably well to a system of dicepools, where you roll for successes.

Dicepool systems can be good for both uncontested and opposed rolls if you take care to design them well (at which point I would contact Dan). They automatically measure degree of success. Dicepool size can be adjusted as a means of handling penalties and bonuses - this would mean changes to the Penalty Die system, but that's okay.

So yeah, that's what's in my mind Monitorswise right now, and to be honest I don't think I'm gonna make any progress until I get some thoughts straightened out. I can't design spells or equipment until I'm happy with a core mechanic, and I can't test the game without spells and equipment.


  1. FWIW I strongly recommend Blackjack as a rolling system. It's mathematically the same as roll-and-add, has vastly reduced search timen and incorporates variable degrees of success intuitively.

    It also covers opposed rolls.

    1. I... understood all of those words, but have no idea what you're talking about. A bit of googling tells me there are ways of doing blackjack with dice, but I don't understand how I'd use them in an RPG. AFAIK blackjack is about drawing arbitrary numbers of cards/dice towards a target number, which allows player judgement but no character skill.

      Can you explain a bit?

  2. Sorry, that was a bit obtuse.

    Blackjack is a type of roll-under system, but the aim is to get as high as possible without going over your skill.

    For example, you could run Deathwatch in such a way that instead of subtracting your dice roll from your skill to find your degrees of success, you just take the tens place of your dice roll.

    For opposed rolls in Monitors it would mean both roll their Attribute, success beats failure but otherwise high roll wins.

    Same results as subtraction or roll-and-add but much quicker search time.

    1. Ah, gotcha. I may well play around with that.

  3. Any views on penalty dice, by the way? It feels potentially interesting, with the right implementation, but I need to think about it a bit more.

    1. I sort of think keeping track of a decrementing penalty, combined with rolling every round to see if you get a one might be a bit awkward, and I tend to feel that just using dice as trackers undermines a lot of the point of using them as dice (I sort of feel if it isn't being used to generate a random number you could just as well write stuff down).

      I'd point out, though, that if you were using blackjack rolling, you could just roll your Penalty Dice every round, and require the action die to exceed all penalty dice (or if you want to be really nasty, the sum of all penalty dice).

      So if you've got, say, D6 of Blind, you would roll 1D20 + 1D6, and if your D20 roll is less than your D6 roll you fail due to blindness.

    2. Yeah, I was thinking of the penalty dice idea as a whole rather than that specific implementation... I'm quite liking your idea there and will try to some some playing around with that.