Wednesday, 5 February 2014

Monitors blackjack

At (inevitably) Dan's suggestion, I am looking at switching Monitors over to a d20 'blackjack' model. For those of you who, like me, have no idea what the hell that is, it sounds more complicated than it is to do. See below.

Doing Stuff

Our new trial 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.
  • Scores higher than a particular threshold (probably 10 or 15) that still succeed may be unusually effective.
  • Scores lower than a particular threshold that fail may be unusually ineffective.

I haven't outlined very 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.

It's nice to have some kind of degrees of success thing built in for reference, if nothing else. Also players do tend to enjoy them. As the old half-score model doesn't work with blackjack rolling, I've included thresholds with a definite caveat. I'm not sure if I want to incorporate this mechanically or simply leave it as a GM reference tool. It's not necessarily clear how to offer "more success" on a good result, and this applies particularly to attack rolls given the low-wound model I'm using. Increased Penetration was briefly considered, but I felt this would devalue it as a weapon property. It would tend to lead to high-Ballistics characters being mechanically pushed towards low-Pen, high-Strength weapons, as they'd gain more benefit from their skill than with high-Pen weapons.

An advantage of the threshold system outlined above is that it avoids the old "all hits are criticals" problem. Using a fixed critical roll (20 on a d20, etc.) can end up with an odd situation where the more difficult a task is, the more likely it is that a success will be breathtakingly good. If you need a 19+ to hit, half your successes will be critical. If you need a 2+, only one in 19 will be. It can just seem a bit odd. Here, the success you're capable of getting depends on your skill; a low skill character might pull off a surprise success, but that'll be narration rather than mechanics. Only a really skilled character can pull off exceptional stunts. I... think this is a good thing.

I could, of course, use "more than half your skill" but that's getting mathsy. I could also use a crit confirmation rule, so a 1 is a potential critical but you need a second success to confirm it; fine, but extra rolls.

Combat and injury

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.

Weapon effects are categorised as Hard or Soft. Hard effects inflict serious pain or actual damage to a target. Soft effects impede a target in more specific ways. A particular weapon may have Hard effects on one target type and Soft effects on another.

Hard effects inflict Wounds, usually 1. Wound pools are typically 1-5, with most enemies in the lower end of the spectrum. There are penalties for mildly and severely wounded creatures. Vehicles and other non-living entities use a similar model with Wounds representing general integrity or particular components.

Soft effects inflict a Penalty Die sized 1d4 to 1d12. This is rolled at the start of the character's turn. On a 1, the penalty has elapsed as the effects wear off (not possible on the first turn). Otherwise, whenever the effect would plausibly hamper an activity, die rolls that do not exceed the Penalty Die fail regardless of Attribute scores. The Soft effects I intend to implement are Blind (impaired senses) and Slow (reduced reaction, movement speed and/or coordination).

I still need to decide whether this comparison happens with or without modifiers. Allowing modifiers (which will often be positive) would probably make things easier for the PCs, who are more likely to look for and exploit bonuses than NPCs.

A character with particular levels of injury may acquire a Wound-based Penalty Die, typically 1d4 when moderately injured and 1d6 when badly injured. These behave in the same way as Blind and Slow dice but apply to all die rolls. Wound Dice are also not discarded when a 1 is rolled.

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

Opposed rolls

Opposed rolls are handled through a roll-off. The highest success wins. Disparities of 5, 10 and so on between scores may indicate particularly spectacular triumphs.

If neither party succeeds or there is a draw, the group must determine whether mutual failure or a draw make any sense in the contest. In many cases one or other party must come out on top: either you wrestle free of the tangleslime's tendrils or you don't. In these cases, roll until an acceptable result comes up (or, in the case of a draw, flip a coin).


  1. Some more quick observations about Blackjack rolling.

    Under Blackjack you could dispense with Armour Saves, and simply have Armour represent a *minimum* you need to roll on your attack in order to inflict a Wound. The downside of this is that it is possible for armour to render a character invulnerable to character with low attack skills. Or if you wanted something more random you could add an enemy armour die to the pool as a penalty die.

    On opposed rolls: Rather than have two fails mean a draw, you could just have high fails beat low fails (so a roll of 20 that fails beats a roll of 18 that fails). Effectively you do badly but your opponent does worse.

    On penalty dice: If modifiers apply to your *skill* rather than to the roll, then they should be independent of penalty dice. I think tracking modifiers *to* penalty dice is probably fiddly.

    1. On opposed rolls: Rather than have two fails mean a draw, you could just have high fails beat low fails (so a roll of 20 that fails beats a roll of 18 that fails). Effectively you do badly but your opponent does worse.

      Huh. I thought I said that, but apparently I didn't. Looks like I got distracted by the "does this make sense" bit. I think my actual intention was:
      1) If one persons succeeds by more, they win.
      2) If nobody succeeds, but this makes no sense, highest failure wins.
      3) If there's a draw and this makes no sense, flip a coin.
      4) Otherwise resolve as rolled.

      Interesting point, but I'll probably stick with them as-is for now. It seems like it works and right now I really just need function. Might look into these ideas properly later.

      Off the top of my head, it seems like there'd be a problem in that armour effectiveness becomes extremely swingy because of thresholds, as with damage reduction models. Armour that's 50% effective against a hardened merc is invulnerable to militia, and you'd get the threshold effect at the point where "never" switches to "sometimes".

      On penalty dice: on reflection, this is a non-issue. Modifiers will definitely be to your attribute because otherwise it gets a bit insane - negative mods would be good by increasing your chance of success but make you less likely to succeed well, and positive mods would generally be unwanted but would help you in opposed rolls except when they didn't. I want a nice simple + good, - bad system.

    2. The missing bit (why?) between the list and "interesting" is a quote of your bit about armour. No idea what happened there.

    3. I did worry that invulnerability might be an issue, although I don't think it would be quite as much of a problem as in Deathwatch because of the way the Wound system works.

      The problem in Deathwatch is that any weapon that will penetrate your armour will quite likely one-shot you, whereas in Monitors it will just do one Wound as normal.