Confusion in your hand

[Kaylesh]

{confusion in the ranks} on the field, then drop {thought eater} and  {Thought Devourer}. Let your opponent have both. Enjoy him discarding his hand. For extra effect add {megrim} or {waste not} and get him to draw a nice handful of cards.

[LinkCelestrial]

You could also use {Donate} or {Baazar Trader} to pass the pieces around. I like it.

[rarehuntertay]

His hand would only be down by 3 or 4, whichever one was on the field first

[rarehuntertay]

Layers. Both are trying to modify the same thing. I will post in rules so the Great Remillo can answer.

[Kaylesh]

I will jack this explanation from Remilio since this is just how I figured it would work:

In the end, they do in fact Stack.

If you apply them in timestamp order, here's what happens:
Devourer says "Your Max Hand Size is reduced by 4"
Eater, with a later timestamp says "Your Max Hand Size is reduced by 3"

However, just because there's something else effecting it doesn't mean the older one doesn't apply anymore.  If you have both on the board, your hand size will be reduced by 7, which in most cases will make it 0.  This is the same as the Cursed Rack ruling, as Cursed Rack would Timestamp like this:

Cursed Rack says "Your MHS is 4."
Devourer says "Reduce it by 4"

Leaving you at 0.  If it were opposite,

Devourer says "Reduce it by 4"
Rack says "Set it to 4"

Leaving you at 4.

Basically, the only time you 'ignore' previous timestamps is when it is going to Set the hand size.  If it's multiple effects that add or subtract hand size (Eater, Devourer, {Locust Miser}, {Minamo Scrollkeeper}), you'll end up just adding them up to find the change.

Savvy?