Ostarius - Nadair Tribe Power Interaction

[Artymysia]

Nadair's Tribe Ability: "Pay 1 crystal to place a forest tile on any vacant desert space. You must pay for the range to this space (from your nearest building or population marker). Owners of buildings adjacent to the new forest tile advance on their green machine tracks as normal. After having placed the tile, you gain 1 book for this tile and for all other forest tiles connected to this tile in an unbroken chain of forest tiles"

Ostarius' Tribe Ability: "Pay 1 crystal (and for range) and place a gate (open or closed) on any vacant sand or terrain spaces on the board. Range can be counted to any of the spaces covered by the gate tile. Advance on the corresponding machine tracks for each space
covered"

Question: I'm using Ostarius' tribe ability to place a gate. I wanted to place it on a three-terrain spot where one of the forest terrain was from Nadair's tribe ability. Is this legal? I've scoured both rule books and haven't found anything to forbid me from doing so. But this wasn't allowed on BGA. Forest is a terrain. If the ruling sides with being prohibited, then Ostarius has a direct tribe that counters them. In the early game, Nadair can rush their forest tiles, and prevent Ostarius from using their tribe power optimally. Nadair is already one of the strongest factions.

[Matindo64]

Make a bug report

[Akahige1979]

The Ostarius tiles can only be put on vacant sand or terrain spaces. It cannot be placed on other tiles. The forest tiles of the Nadair are exactly that, tiles. So you wouldn't be able to place an Ostarius tile on a Nadair tile. Whether that gives the Nadair an unfair advantage or not is another question, but that's how the rules work.

[Artymysia]

What you're saying is a contradiction for the Nadair-Formica Tribe interaction; and the Vukuntor as well.

Formica: "Starts with 5 Workshop tiles"

Tribe power: Pay a crystal to place a workshop on any terrain
space (field, mountain or forest). You do not need to pay for
the range. Immediately advance 1 space on the machine track
matching the terrain type.

They are called 'workshop tiles' explicitly in the rules. The Nadair's are called Forest Tiles. Intuitively, tiles shouldn't go on top of tiles if the mechanic isn't inherently built into the game; especially if one were playing in person---it would just be weird. Yet this interaction is legal on BGA. I just tested this out.

Opponent puts down Forest tile from Nadair's tribe power, and then I plop my Workshop down on top of it. I've also tried this with Vunkuntor. Both are allowed. If this is the case, why is Ostarius an exception to the rule?

The answer must lie in Revive's definition of 'vacancy' and 'tile'. But however I spin it, there is always a contradiction in the prevailing mechanics that BGA allows. I would love for the Dev or one of the creators to chime in. I don't want to report a bug and waste someone else's time if I'm overlooking something.

[HelgeM]

Hi,

"vacant" is indeed what makes the difference. After checking, I think the rules are consistent and also implemented on BGA.

"Tiles", as in playing pieces, have slightly different rules depending on the tribe.
But all "tiles" that are shaped like terrain (sand tiles, forests, gates) cannot be placed on top of anything else. One reason is that that would just be fiddly in the physical game.

Workshops, targets and the falcon are not restricted in the same way, they follow other rules.