Thursday, September 9, 2010

Force Bubble

So I'm going through the InDesign layout program and touching up the stuff I've done and I come to the area for the Force Bubble power.

Force Bubble is an attack that traps the target in a floating force-field bubble that they can blast their way out of (if their attack is powerful enough). It's an odd power. I discuss it with the gang. I'm posting about it here because (a) it's "what I'm doing right now with JAGS" and (b) it shows how there are all kinds of edge-cases everywhere.

Is It A Tangle Attack?
Kind of. But maybe 'not really.' Tangle attacks (like nets, glue guns, etc.) roll to hit and then there's a "roll to see if you are tangled" and by "how much" (grab? hold, etc.). The Force Bubble could conceivably fail to 'bubble you' but if it does it's kind of "all or nothing." Our vision of it is that you are not generally "half inside the bubble."

Secondarily, unlike a web-shooter or whatever, if you are inside the bubble you have a free range of motion. Our vision is that the interior of the bubble is kind of 'zero gravity' so you're floating there (and the bubble is floating) but you can freely use your arms and legs, fire a weapon, etc.

If you target someone outside the bubble you can still shoot at them--but the bubble acts as armor (maybe) and DP that interdicts attacks both ways. So it's not really a Tangle Attack in that it doesn't pin your arms, give you negative Damage Modifiers to attack it or others, etc.

So: not really a tangle.

Force Field or Armor?
The simplest way to handle the bubble is that when hit you are encased with some amount of Armor (say 4pts) and some amount of 'DP' (really ADP), say 10pts per level. If you attack the bubble itself you get +5 to hit it (doing more damage). If you attack someone outside the bubble you roll to hit them and the attack is reduced by first the Armor and then the DP. Anything that gets through pops the bubble and continues on to them.

That's pretty simple on the face of it.

However, the most 'correct' way to model this isn't with Armor but with Force Fields. Force Fields reduce damage much the same way armor does but they then degrade. If the damage done is half or more the field's power but less than its full defense the field is reduced by Total Damage/10. If any damage gets through the field the field is reduced by Total Damage/5. Let's see an example:
A Force Field has 10 pts of Power at full strength. It is shot by a 9mm hand gun (Base Damage 6 PEN) that hits for 9pts (+3 Damage). NOTE: assume the attack does not penetrate. As the attack does not exceed the current power of the field (10pts) but does exceed half it's current (5) power the field is reduced by Total Damage/10 or 1pt. The field now has 9 Power.
 Now, note that this power (Force Bubble) is listed under Energy Control in the Innate Powers section. One would, in theory, expect a "Force Bubble" to use the Force Field rules. However there are some reasons not to. Let's look at the arguments.

  1. Against FF: Complexity. Keeping track of Force Field degradation for a field that isn't protecting a character is complex for no explicit material gain. If the group forgets what the current state of the field is then there are all kinds of problems trying to figure out what it should be.
  2. For FF: Makes Sense / Principal of Least Surprise. Ideally things should work 'the way a person who hasn't read the rules thinks they ought to.' This applies to powers like Force Bubble but more consistently to rules like grappling, falling, and drowning (yes: I'm aware the last to get special derision in some circles!). If you throw someone off a skyscraper you expect them to fall for lethal damage. If you are held underwater you expect that, eventually, you'll die. If you fire a weapon called "force bubble projector" you might well expect a force field.
  3. Unclear: Power Curve. Both Force Field and Armor behave differently--very differently. Let's say that the power gives 4 Armor or 6 Force Field. In the Armor case a character who does, with a strike, 4pts of damage will never penetrate it (in reality they will because the strike will do more damage--but lets say they have a Base Damage of 1 and can therefore get at most +3 unless they kick or throw crosses). In the case of the Force Field, they will. The speed at which a more powerful attack (say, a handgun) will blow through the bubble will change as well. Against the Armor it'll take longer because even though the FF starts higher, it goes down rather quickly (very quickly if they can exceed it with the damage dealt). Which version is right? That depends on the role Force Bubble is expected to play when being used against a peer. Without knowing that we can't say which is right or wrong!
  4. Unclear: How is PEN Damage Handled? Another question that varies is how is PEN damage supposed to be handled? Our first thought was that the bubble should take nothing but IMP damage (no vital targets or weak spots) but that poses a problem: if I fire at a target outside it what do I do? I can add the bubble's PEN defense to the target's but what damage do I apply to the bubble itself considering that if the Armor Save does fail, the attack will do more damage (this creates the nonsensical situation of characters wanting to break the bubble firing at soft targets outside the bubble to try to get a PEN doubling result!). Armor and Force Fields typically handle PEN damage a little differently (Force Fields never get Penetrated if their current power x 5 is more than the Base Damage, Armor gets an Armor Save). Which is better?
  5. Unclear: How Long Should It Last? Since most characters--even normal people--could break through a 6pt FF (the theoretical value of its field) if you plan to 'bubble up' criminals and leave them for the cops it won't work as well as the Armor will (assuming you have enough Armor to shut down their attack). Should you be able to bubble someone (far weaker) than you and walk away? If the answer is "yes" that speaks to either Armor or, at least, more than the nominal allocation of Force Field. If the answer is 'no' then the choice goes the other way.
The Role Of Force Bubble
So, okay: we need to know the role of Force Bubble now and answer those questions above. Let's take a stab at it.
  1. Vision For Holding: I think of Force Bubble as kind of a "space ranger" power where the guy swoops in and bubbles you and if you're just a punk, you're stuck. Clearly against a powerful character the bubble will not long contain them--but it should be able to hold a bank robber for a while (maybe at Level 2). This speaks to Armor or more FF.
  2. PEN Defense Decision: I don't want the bubble to take PEN damage often which is good for the Force Field choice--however, another solution is simply to give it a much higher PEN defense than its nominal level of Armor would imply. 
  3. Level Of Defense: If we assume that an average bank robber will have a 9mm (6 PEN) that, against the bubble can get a +3 Damage Mod (it is forced to roll on the Impact Damage Table) dealing 9pts of Damage on a likely hit then either armor of 9 or Force Field of, like, 18 will stop it. If we assume that this is level 2 (16 AP spent on the bubble power) then that gets us 4.5 Armor or 9 FF per level.
  4. Curve Of These: Let's go with 5 Armor per level to make things simple. If we give the bubble 5 Armor and 10 DP then a Level 1 Power Blast (14 damage) can blow its way through in roughly one shot (assuming it's trained on the bubble so it gets +1 or better). Against the Force Field version the 15 points of damage will exceed the field doing 5 damage to the DP and reducing the field from 9 to (15/5=3) 6 defense. This means the FF version is tougher on the 1:1 match-up.
  5. Conclusion: as I want the field to pop on one hit from a similar attack. That leads us to Armor.

What Other Rules Do I Need?
Discussion around the Force Bubble power yielded these further questions/observations:

  1. You cannot Force Bubble Godzilla even for a second with a little bubble gun. There must be a BLD limit on what you can encase based on the Power of the Bubble. Let's say 20 BLD per Level? Something like that.
  2. Bubbling Darth Vader is just undignified. As we are considering allowing a 'reaction move' to use your strength, gun, or light-saber or whatever to break through a Tangle we should allow this against the bubble too. Even though it's not a Tangle per-se it needs to trip that rule.
  3. We need rules for what happens if (a) you bubble someone twice (probably not much. Maybe you add some DP on to it) (b) if they are in a grapple or grab (probably you add the BLD of whoever they are with and if it's under the limit you get both (c) what happens if they are literally attached to something (probably the simple rule is that if they are just 'hanging on' it gets them, if they are /connected/ you use the BLD of whatever it is, and if you are using advanced rules it has a Grapple Attempt to break their hold on it)
  4. How long does it last? Is it waterproof? Could you use it to survive in space, etc. (Standard answers are: it lasts a few hours, it will keep water out and air in but will not suffocate people if there is air outside, and it'll keep you alive in space so long as the air holds out.
  5. Can you use Force Bubbles to build things? Connect them? Etc. Probable answer: they are sort of fixed in space (even in air) so they don't roll around like marbles (but can be dragged). They don't stick together easily at all (maybe with TK or Tractor Beams)
  6. What About Fast Company Characters. In JAGS a class of characters have negative Damage Mods and are hard to hurt--but not all that hard to hit. Tangle attacks and things like the bubble are an anathema to them as once you have them sort of pinned down they lose a lot of advantage (they also tend to do Low or Very Low damage making their speed and defenses cheaper so they are more vulnerable to the bubble). We don't want to 'punk these guys' so we need to think about how to handle that. The way we think is best is to make things like the bubble attack easy to dodge
  7. What if the target is moving or falling? Can you save someone falling from a plane by putting them in a floating bubble (yes: if they aren't going too fast).
This is the sort of thing that we need to think about for every ability ...



  1. It probably doesn't help that force fields aren't always force fields.

    What I mean by that is that there are examples in various genres (superheroes come noticeably to mind here) where there's no sign that the force field degrades; in fact, in some the only reason they ever collapse is the individual/equipment simply isn't functional any more.

    So you're going to get issues where some force field like effects aren't going to use the force field mechanic anyway.

  2. This is true. Even in JAGS there are several 'force field like' things (Power Field which is like ADP but gives PEN Defense and Radiant Armor which looks like 'a force field' but acts like armor). So, yes--all true. One of the reasons I didn't put too much emphasis on it being a mechanical Force Field.