[RPG] In D&D 4E, can a changeling change its biological sex

There is some disagreement on the Wizards' forum on this as well.

There is a ruling from customer service in 2008.

You must be 3 squares AWAY from the square in which you started your turn. If you end your turn only two squares away from where you started you will not gain concealment with Shadow Walk.

A ruling from 2009 contradicts that.

In order for the Shadow walk to trigger the warlock needs to move at least 3 squares away from the starting square. He does not need to finish his move 3 or more squares away from the starting square

Incidentally the PHB3 glossary explicitly defines movement as

Whenever a creature, an object, or an effect leaves a square to enter another, it is moving, whether that move is done willingly or is forced. This means shifting, teleporting, and being pushed are all moves, for example.

So if you were to teleport 3 squares on your turn (through a non-immediate power though please!) you should trigger Shadow Walk.

A good way to analyze the differences between the two distributions is to imagine a head-to-head contest between characters.

First, suppose you have two identical characters, A and B, rolling off against each other with d20. They tie 5% of the time; 47.5% of the time one wins; 47.5% of the time the other wins. In contrast, if you use 3d6, ties occur 9.2% of the time and each wins 45.4% of the time. Not a huge deal. Let's discard the ties and just concentrate on who wins more, A or B. Now let's start giving them bonuses. Since we haven't said who is whom, we'll just declare that A is the stronger one and B is the weaker one.

A's bonus  3d6                     d20                    3d6 ratio
=========  =====================   =====================    over
=========  A-wins  B-wins  ratio   A-wins  B-wins  ratio  d20 ratio
---------  ------  ------  -----   ------  ------  -----  ---------
+0         45.36%  45.36%    1.0   47.50%  47.50%    1.0      1.0
+1         54.64%  36.31%    1.5   52.50%  42.75%    1.2      1.2
+2         63.69%  27.94%    2.3   57.25%  38.25%    1.5      1.5
+3         72.06%  20.58%    3.5   61.75%  34.00%    1.8      1.9
+4         79.42%  14.46%    5.5   66.00%  30.00%    2.2      2.5
+5         85.54%   9.65%    8.9   70.00%  26.25%    2.7      3.3
+6         90.35%   6.08%   14.9   73.75%  22.75%    3.2      4.6
+7         93.92%   3.59%   26.2   77.25%  19.50%    4.0      6.6
+8         96.41%   1.97%   49.0   80.50%  16.50%    4.9     10.0
+9         98.03%   0.99%   99.0   83.50%  13.75%    6.1     16.3
+10        99.01%   0.45%  220.0   86.25%  11.25%    7.7     28.7
+11        99.55%   0.18%  552.9   88.75%   9.00%    9.9     56.1
+12        99.82%   0.06%  1663    91.00%   7.00%   13.0    127.9
+13        99.94%   0.02%  6661    93.00%   5.25%   17.7    376.0
+14        99.98%   0.00% 46649    94.75%   3.75%   25.3   1846.3

Okay, so what does this tell us?

First, we can see that with big bonuses, A slaughters B head-to-head in rolls in 3d6, whereas with d20 the benefit that A gets over B is pretty modest (has to get all the way up to +11 before A is tenfold more likely to win than B!).

But, second, if you look at the ratio of ratios (that is, how much advantage A vs B has in 3d6 compared to A vs B in d20), you find that in 3d6 the bonus is pretty much squared compared to d20 (low values only--then it gets way, way more extreme later on).

So, what does this mean? Well, basically, if under 3d6 you have a +1 bonus more than someone else, it feels like a +2 difference in d20. +7 feels like +14.

So the concise explanation is: moving from d20 to 3d6 amplifies differences, making them feel about twice as large as before. (Of course, almost nothing is actually resolved as a head-to-head test, but it's a useful thought experiment.) You can cleave through hordes of lesser beings with that much more ease, and your betters become that much more fearsome. In fact, better just stay away from them. There are some kobolds that need slaying. Right? Right.