Is "*/*" considered a "+X/+X" counter or as the "base power" of a creature spell?

Question

I have a card (namely Molimo, Maro-Sorcerer) which has "*/*", where "*" is equivalent to some condition. My opponent has a spell (namely Vorinclex, Monstrous Raider) with

If an opponent would put one or more counters on a permanent or player, they put half that many [...] rounded down.

Does the "*/*" of my creature behave then as a "+X/+X", which would be halved by my opponent's spell, or is "*/*" my base power/toughness? It seems to me the "*" is a value defining the base power/toughness rather than counters added to a base of "0/0".

But my interpretation is obviously biased by my desire to win. I expected to find answers to this in Rules 208 or 613, but did not.

Answer 1

+1/+1 counters are counters. They are, per CR 122.1, specifically added to the permanent or player:

122.1. A counter is a marker placed on an object or player that modifies its characteristics and/or interacts with a rule, ability, or effect. Counters are not objects and have no characteristics. Notably, a counter is not a token, and a token is not a counter. Counters with the same name or description are interchangeable.

Creatures that are */* don't have counters on them by default. This means for example that their power and toughness are not affected by proliferate, Vampire Hexmage, nor the effect that says any +1/+1 counters on your opponent's creatures are halved and rounded down. So your interpretation is correct.

The edge case is for a creature like Walking Ballista, which has 0/0 stats but also enters the battlefield with +1/+1 counters. In this case proliferate, Vampire Hexmage, etc, can affect it. Still, Walking Ballista is not a */* creature; it is fundamentally different.

Answer 2

You are correct that the value defined for */* is considered the "base power and toughness" of the card, exactly as if it was printed there. Rule 208 covers the two ways a creature card can define its P/T (emphasis mine):

208. Power/Toughness

208.1. A creature card has two numbers separated by a slash printed in its lower right corner....

208.2. Rather than a fixed number, some creature cards have power and/or toughness that includes a star (*).

208.2a The card may have a characteristic-defining ability that sets its power and/or toughness according to some stated condition. Such an ability is worded “[This creature’s] [power or toughness] is equal to . . .” or “[This creature’s] power and toughness are each equal to . . .” This ability functions everywhere, even outside the game.

Characteristic-defining abilities are not counters, they are intrinsic parts of the card, so much so that they apply even when the card isn't on the battlefield. +1/+1 counters, in contrast, are only ever found on cards on the battlefield.

Further confirmation that these effects are not considered tokens is found in rule 613, where they are applied in different "layers":

613.4. Within layer 7 [of applying continuous effects], apply effects in a series of sublayers in the order described below....

613.4a Layer 7a: Effects from characteristic-defining abilities that define power and/or toughness are applied.

613.4c Layer 7c: Effects and counters that modify power and/or toughness (but don’t set power and/or toughness to a specific number or value) are applied.