D&D 4E Non-Euclidean Geometry in 4E?

[AZRogue]

If Defenders don't receive abilities and powers that let them shift when it's not their turn, stop attackers from passing them, etc. then I will definitely house rule things back to diagonals = 1.5

 

[Nom]

How so? You’ll have to illustrate this with an example. The directional constraints are a lot less than squares and the distance constraints are small.

Maximum deviation from direct line is 30 degrees on a hex grid and 45 degrees on a manhattan grid. Thus, if we call the distance moved 1 (conveniently making it the hypotenuse), then the straight-line distance is cos 30 (0.87), 13% less, for hex and cos 45 (0.71), 29% less, for manhattan.

Yep, hexes are more accurate. I've also noticed 5 or more sided regular polyhedrons tend to be approximated by the brain as "sorta-circular" while 3 or 4 sided figures are not.

However, both hexes and manhattan feel - at least to me - restricted, that I'm moving in allies rather than freely. The 3.5 metric felt - to me - like "real" distance. Whether that was because the deviation was only 22.5 degress or that the uneven metric obscured the grid I don't know. Deviation is trickier, since (for example) moving 2 up and 1 across costs 2.5 squares of movement (1 diagonal, 1 straight) rather than 2.41 - the straight line is thus 10.5% shorter that what you actually pay, which is pretty close to that for hexes.

And, DND is not played with orthogonal movement only.

Quite true. Nor is it played in only 3 axes. Any game on a gride ultimately fixates around the axes of the grid, which is one reason that more axes (even with non-simple metrics) provides fewer restrictions to play.

Beyond that, I find it easier to think in the 8 cardinal directions, which is why deviation on a diagonal square grid feels less "annoying" to me than deviation on a hex grid. The inherent limitation of the grid is off-axis and thus not as visible.

Draw a line or hold a string up. Cover exists if a hex has 50% or more of it on the side granting cover. That’s just as easy of a rule as "if a line drawn through any" of 3.5 for squares.

Huh? How does that work if I run a long line across two adjacent hexrows, where it spends a large amount of time clipping alternate hexes? Yes, you could rule on the 50% crossing point, assuming you can eyeball this accurately, but that isn't nearly as simple as "if it clips it, it's in".

I fail to see this as hindering game play in any way.

Obviously you're better at on-the-fly trig than I am; I struggled with it for about 6 years of playing Battletech, and is why I loathe mixing hexes and LoS.

Really, I know this has very little to do with the change from 1,2,1,2 counting and diagonal=1 counting, but it rubs me the wrong way. However, in "manhattan geometry" or a hex grid this situation is not present (or at least a lot better hidden), which I think is a decent enough argument for using one of those systems.

It's a function of degrees of freedom. With 2 axes, you only need 2 people to block half the movement options. With 3, you need 3. With 4, you need four. Try your example again with hexes by rotating onto the hex-row - you either need to block along a hex-row (and thus not truly normal to movement) or have a double row in the same way as diagonals need a double row.

The number of "extra" people compared to a "true" example is dependent on the error of grid-row to actual path. The 1.5 case is a little odd, due to the difference in movement metrics in each axis.

 

[delericho]

Not necessarely. The area of effect you're describing looks a bit more like a 12.5' radius circle anyway. Which would indeed be 5pts in a 5' = 2pts metric.

10 ft. reach should indeed be plotting a 12.5 ft. radius circle - the square in which the character stands doesn't count.

With the "straight = 2, diagonal = 3", I don't think simply multiplying existing distances by 2 is the answer - the 10ft reach case would appear to be one such. However, if we're approaching this as a thought exercise towards a new game then difficulties in converting all the existing distances are irrelevant - all that matters is whether the end result works.

That said, the main oddity with "straight = 2, diagonal = 3" comes simply from counting a single square as 2. So, while it's mathematically elegant, I'm not sure this is a better solution than "straight = 1, diagonal = 1.5"

 

[delericho]

I believe I woud file this change under "mistakes not learned from".

In 3.5, they wanted Power Attack to be more powerful. If you follow the math that is consistent with the rest of the game and is most balanced, you would change it so that light weapons add 0.5 damage for each point of penalty spent, one-handed weapons give 1, and two-handed weapons give 1.5. But, since that would make the math more difficult, WotC decided it was best to damn the math and go with 0-1-2 (respectively) instead.

Here, again, they have decided to sacrifice realism for the sake of quick playability that requires less math, in a way that will be amazingly controvertial, and allows players to munchkinize rounding errors. IMO, they have gone too far in search of simplicity, to the point that it will actually make things more complicated when people learn that they can play games with diagonals.

I think there's a huge amount of truth in this.

 

[arscott]

Hmm. You folks may have a point about hexes and cover. But I just came up with a solution that I think will work pretty well:

Squares
To determine whether your target has cover from your ranged attack, choose a corner of your square. If any line from this corner to any corner of the target’s square passes through a square or border that blocks line of effect or provides cover, or through a square occupied by a creature, the target has cover (+4 to AC).

When making a melee attack against an adjacent target, your target has cover if any line from your square to the target’s square goes through a wall (including a low wall). When making a melee attack against a target that isn’t adjacent to you (such as with a reach weapon), use the rules for determining cover from ranged attacks.

Hexes
To determine whether your target has cover from your ranged attack, choose a corner of your hex. If both lines from this corner to any two adjacent corners of the target's hex passes through a hex or border that blocks line of effect or provides cover, or through a hex occupied by a creature, the target has cover (+4 to AC).

When making a melee attack against an adjacent target, your target has cover if a wall or obstacle (including a low wall) passes through the adjoining edge of your hexes. When making a melee attack against a target that isn't adjacent to you (such as with a reach weapon), use the rules for determining cover from ranged attacks.

 

[Steely Dan]

Try to run your next adventure with this system of counting squares. Pick a module at random, use 4 pregen PC's and test it out.

Come back when you've finished and share your results. Right now I'm seeing all sorts of hypothetical sitations that are just that - hypothetical. The real test is in play.

Tried it out in a one-off combat between a Hezrou and 3 vrocks against a party of 5 characters (a psion, spirit shaman, barbarian/ranger, psychic rogue and a fighter/divine bard/hammer of Moradin), and it worked out just lovely, especially with the withdraw rule from Saga and the new charge rule from DDM – lots of ebb and flow juiciness.

 

[HeinorNY]

Tried it out in a one-off combat between a Hezrou and 3 vrocks against a party of 5 characters (a psion, spirit shaman, barbarian/ranger, psychic rogue and a fighter/divine bard/hammer of Moradin), and it worked out just lovely, especially with the withdraw rule from Saga and the new charge rule from DDM – lots of ebb and flow juiciness.

The new charge rule is from Saga too.
Note that in Saga, diagonal movement is 2-2-2-2, so the new charge rule really isn't there to "fix" the weird diagonal move at all.

 

[Steely Dan]

The new charge rule is from Saga too.

No, we're using the new charge rule from 2.0 DDM (standard action, do not have to charge in a straight line, can move through an allies square).


We are using the withdraw rule from Saga, though (move action, up to have your speed).

 

[delericho]

Tried it out in a one-off combat between a Hezrou and 3 vrocks against a party of 5 characters (a psion, spirit shaman, barbarian/ranger, psychic rogue and a fighter/divine bard/hammer of Moradin), and it worked out just lovely, especially with the withdraw rule from Saga and the new charge rule from DDM – lots of ebb and flow juiciness.

I hate to have to ask, but...

Firstly, how sure can you be that the "ebb and flow juiciness" came from the new diagonal rule, and not from the withdraw and charge rules?

Secondly, and more to the point, did your resident power-gamer go out of his way to try to abuse the rule?

Because to a large extent that's where the problems are going to lie. Aside from some cognitive dissonance from those of us who are offended by such things, the rule will play just fine in the 'normal' cases. However, as soon as it hits a player who is out for every advantage that they can get, it will fold up like a cheap umbrella. And there is are a very great many such players out there, many of whom have been trained in that very characteristic by the relative rigidity of the 3e ruleset.

Just before Christmas, I ran an absolutely disastrous Shadowrun game for all of two sessions before it imploded. When I analysed just why the game had collapsed, I came to the conclusion that the designers had built the game under the assumption that the players would 'play nice'. Naturally, my resident power gamer had immediately latched onto the Troll race, maxed the Body attribute, boosted it further with cyberware, and then layered on armour on top of that, generating a character who was completely immune to harm.

It is one of the great strengths of 3e that the system is so robust. The various exploits that have been found have actually been relatively few, given the vast player base, the thousands of pages of official supplements, and the lifespan of the edition. Much of that is that the designers didn't stint on the mathematical rigour when building the system. It now seems that that rigour is being sacrificed in the name of 'fun', which concerns me greatly.

 

[HeinorNY]

No, we're using the new charge rule from 2.0 DDM (standard action, do not have to charge in a straight line, can move through an allies square).

Yeah, that's new.
Since you are using the new new charge rule, let me ask you: Why isn't everybody charging all the time?