Can a character reduced to Tiny size but originally bigger use his Dexterity modifier for Climb checks?

Question

In Pathfinder, Tiny or smaller creatures use their Dexterity modifier for Climb checks instead of Strengh. It is quite easy to understand in terms of game balance and common sense alike.

But then I wondered something : if a Small or larger creature (then having to use Strengh to climb) is reduced to Tiny size or smaller, can it use Dexterity for Climb checks ?

In the opposite case : Does a Tiny or smaller creature have to use Strengh for Climb checks if it gets enlarged to Small size or larger ?

Answer 1

The rule for tiny creatures does not specify only "naturally" tiny creatures. It is a blanket statement -- if you are tiny or smaller, you use your dexterity modifier. Other rules that apply to tiny creatures apply to creatures made tiny by reduce person (bonus to AC, penalty to STR, etc), and I see no reason to think that this particular rule is any different. The wording for tiny creatures who want to make a climb check is clear, in that it applies to any tiny creature.

Any creature of Tiny or smaller size should use its Dex modifier instead of its Str modifier for Climb and Swim checks. (Source: d20 PFSRD)

And from the official Paizo FAQ:

Tiny creatures, Climb, and Swim: Should all Tiny creatures use Dex instead of Str for Climb and Swim skill checks, or is that just for familiars?

Any creature of Tiny or smaller size should use its Dex modifier instead of its Str modifier for Climb and Swim checks. This will be added to Bestiary 4 as a new Universal Monster Rule. (Source: Paizo FAQ)

Though it is not explicit, this rule should apply universally to all creatures, not just monsters.