Movement speed decrease Stacking

[axiris]

Awkward title I know, but it's the best way I could think of to describe it.

Basically, I want to know how effects that decrease movement speed stack with one another.

In this case, Slow (Halves Moment speed among other things), Entangled (Also halves movement speed among other things), and the Solid Fog spell (Also also halves movement speed among other things).

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For example, assuming we begin with a creature with a 30ft movement speed, would it look something like this.

Creature is affected by slow (Speed drops to 15ft/rnd).

Then the creature is entangled (Speed drops to 7.5ft/rnd, rounds down to 5) <--- This is the step I begin to be unsure I was right

After that, a party member throws a Solid Fog on the same creature, further reducing it's movement speed to 2.5/rnd, or rounded down to 0.
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At least that's how I thought it should go, it ended up not mattering since the thing's turn didn't come up, but I was wondering if I interpreted how it should work correctly with those effects stacking.

[Frankthedm]

Yes, those all stack.

Minimum Movement: Despite whatever penalties to movement you might have, you can take a full-round action to move 5 feet (1 square) in any direction, even diagonally. This rule doesn't allow you to move through impassable terrain or to move when all movement is prohibited. Such movement provokes attacks of opportunity as normal (despite the distance covered, this move isn't a 5-foot step).