River math feels weird

[Delokris]

So tried the river tile and found it a little weird how it worked.

Tested it with thickets (+2% Attack Speed). Placed a thicket next to a river and got 4% added as expected but when I placed a thicket next to two rivers I got +8% which surprised me because I thought they wouldn't stack. So I went even further and placed a thicket next to 3 river tiles and got 12% added. So the bonus is not multiplicative but additive. The way I think it works is the river doesn't double the effect of adjacent tiles but removes the effect from the tiles and adds the doubled effect itself. This way the first river would notice a thicket next to it and set the effective bonus this thicket gives to 0 and the river gives the doubled effect of 4%. The second and third river would also notice a thicket next to themselves. They would also set the effective bonus to 0 and give a 4% bonus themselves and therefore an effect of +12% Attack speed.

Why this feels weird is the description of the river tile which "doubles the effect of adjacent landscape tiles". If it truly doubled the effect, the thicket should give 8% with two rivers and 16% with three rivers (if it doubles the already doubled value) or 6% with two rivers and 8% with three rivers (if every river just doubles the base effect).

So I don't know how I feel about this. It's just way better to fill as many tiles with rivers with one space between them for thickets and presumably forests, rocks, mountains and meadows. In my experience, you get way more rivers than other landscape tiles if you don't place forests or rocks so this strategy seems even better than leaving enough space to place as many landscape tiles as possible which in my opinion should be better for rewarding long term planning.

[Tyrant]

Rivers were nerfed, the multipliers are:
2/4/6/8x

Before that, with true doubling, they were absolutely broken.

If they only gave +1x per additional river, as you mentioned, there would be hardly any reason to run rivers as you'd get the same benefit by just placing that tile down instead.

The way it currently works is a compromise to keep the tile from being broken, while also retaining its usefulness & making it require some thought on how to place.

[Delokris]

First of all thanks for the explanation.

It is understandable that true doubling would be way too strong. But in my opinion, there would still be enough of a reason to take it in your deck if it only gave + 1x per additional river. It basically would increase your chances to get the effect of landscape tiles. Assuming every card is evenly likely to drop and you have 10 cards of which one is a landscape tile you want to get as many of as possible you would have a chance of 10% it drops. If you add the river card you would increase your chances from 1 out of 10 to 2 out of 11 which would be around 18%. So you would nearly double your chances.

[Doombringer]

Landscapes drop WAY more often than other cards.
roadside/path/special cards are weight 2-4 (except wheat field is 6)
Rock/Mountain & Forest/Thick are 12+10
Desert/Dune is 10+8
Suburb is 18
Meadow is 15
River is 14
You generally want less, not more.

Once you have bridge river can be a landscape that also make lots of mob spawners if you really want.

Rivers are better than just straight land though - lets say you do simple full columns:
thicket + river = 4% = 2%/tile, okay...
thicket + river + thicket = 8% = 2.67%/tile (river+thicket+river is the same)
thicket + river + thicket + river = 12% = 3%/tile (again, same if you start with river)
thicket + river + thicket + river + thicket = 16% = 3.2%/tile (also same if you start with river)