vicawoo
Chieftain
- Joined
- Feb 12, 2007
- Messages
- 3,226
Disclaimer: a work in progress. Feel free to contribute.
Scouting is important. Many are people are inefficient. Hence, some algorithms that maximize the scouted area per turn.
Mechanics
A reference which explains later algorithms.
A unit sees all adjacent tiles. Screenshot unnecessary. And thanks for reminding me you can see hills one extra tile away. Sentry units will see them 3 tiles away.
A unit sees two tiles in every direction across water (including lakes), if the line of sight is not blocked. That will be explained in the land example. If a piece of land is across one tile of water, you will see it.
On a hill, you will see two tiles in every direction if not blocked by line of sight. This does not combine with the water line of site, so you will not see 3 water tiles when on top of a hill. You will see 3 with sentry, but I won't talk about that.
This screenshot shows all necessary examples of line of sight. Notice there is a hill 1 east (1E), so we can't see the tile 2 east (2E).
There is another hill 1SE, so we can't see 2SE. You can see it's a forest, but I'm not going to talk about that.
We CAN see the cow 1N2E even though there is a hill 1E, so we can see around. The LINE is not directly blocked, so we can see it.
In contrast, we can't see 1S2E since it is blocked by those two hills. There is no tile halfway in between, so we'd think we could sneak a peak between the two hills, but they form a complete seal to our line of site.
Finally, there is a forest 1N which blocks our vision of the tile 2N (I moved the scout, so we had vision, but it is in the fog). Forests and jungles block just like hills.
So remember: line of sight, forests and jungle and hills block line of sight.
And finally, diagonals are your friend! Assuming you can only see adjacent tiles, moving 1E will reveal the tiles 1N2E, 2E, 1S2E. If you move NE, you will reveal 2N, 2N1E, 2N2E, 1N2E, 2E. 5 tiles > 3 tiles.
Add screenshot.
Algorithms
The most common inefficient scouting pattern is on the coasts. Here's a dotmap of a corner tile on a coast. Note that cities cannot use the tile 2SW of our helicopter.
Hence there is no point scouting it, at least for scouting city locations.
It is sufficient to scout spot #1 above, which will reveal 1SW, 1S, 1SE, et cetera, 2S1W, 2S, 2S1E, et cetera
along with spot #1 below, which basically covers the eastern tiles.
So if you're scouting the coastline, instead of heading to a corner then moving up, save a turn of scouting by moving to the tile just before, then heading diagonally up.
Due to the map generator's jagged coastlines, this ends up saving a lot of turns.
In the above screenshot, we fully reveal all usable coastal tiles in 5 turns. Whereas if we moved to each corner, it would either take twice as long (10 turns) or we would miss the inner land tiles.
Another example, common in some windy fractal maps.
3 moves is all we need. If we scouted the corners, it would take 5-6 moves.
Sweep arcs and reveal as much as possible
*Under construction
Zigzag scouting
So often backtracking your arc leads you on a fairly straight line. You could just scout a straight line. Or, since moving diagonally takes the same amount of unit moves as moving straight, you get extra scouting by zig zagging 2 tiles back and forth in a direction.
Here's the simplest example: a straight coastline. If we hug the coastline, we only reveal 2 tiles inward from the coastline. Do that for 8 tiles and we've revealed 16 land tiles in 8 turns, along with the sea tiles.
However, if we zig zag 2 tiles in and back, we reveal 3 to 4 tiles in. Note that because of the 2 tile water property, we don't miss any coastal tiles from the first screenshot. A straight line gives us redundant coastal information.
Actually you don't need a coastline, it works with any straight corridor
We can further improve on this by adding a straight line to our zig zags.
Now we always reveal 4 tiles in, which is twice as good as our straight line scout. You cannot do this if you're doing a pure land scout, you will miss the tiles opposite of your line portions If you're curious, mentally check to sea if it grabs all the land and sea tiles.
We can combine the zig zags with the straight lines to gain more scouting. Of course, we can omit some of the straight lines to include more hills for extra vision.
If we do two straight tile moves, we will miss the other side of the zig zag, so be careful.
Of course, you aren't always aware of how far the coastline will remain straight. Moving to 1 in the picture will reveal the water 1N of the deer, and it will also indicate whether the coastline curves in, out, or stays straight to the east of the deer.
You might end up only doing a 1 tile zig zag to anticipate a curving coast (so we can do the corner trick). The zig zag with the straight line will not anticipate the coast curving away, while a pure zig zag will.
You can add zig zags to reveal more territory, but also to get better defensive terrain while not losing any coastal information.
I'll have to include more screenshots on anticipating the coast.
Here we react to the contours. If we saw a straight portion (pretend we started 1S or 1E), a zigzag would be fine if the land moved away (east to west), or lose us at most 1 turn if the land curved inland (south to north).
Planning your arcs
Under construction.
Remember it will take quite a few turns to sweep out an arc and cover another return arc. If you're too ambitious, you may not end up scouting that peninsula on the other side of your city. So consider scouting it first and start curving around.
You start with a scouting unit, which will cover most major arcs. You will often build another unit before you build a settler, and sometimes it will have time to cover smaller arcs in the opposite direction.
Tips
-Coastal resources aren't as valuable early since you have to build workboats for them, so for your first arc around your city, feel free to ignore them. Your next few arcs, scout along them to find neighbors and establish the limits of your arcs.
-Animals spawn at turn 5. They won't spawn within two tiles of your scouting unit, so you have a few more turns. After that, scouts especially are vulnerable on open ground since they effectively get a lower difficulty bonus to animals. So be extra aggressive on scouting those open areas those safe turns, so you can scout safer, forested/hilled areas later.
-Once you've scouted city locations, you can scout those corners to check for islands. Check the tile yields to see if what you expect to be ocean tiles are coastal tiles.
-Your city gets site of every tile within your culture. So remember your first border pop get 2 tile vision from hills in your outer borders, meaning you can scout around it and reveal more tiles instead.
-Your second border pop won't be in time for your second city, and the tiles they reveal could be important. However, as long as huts aren't on, a non-tundra forested tile on most maps will not have a special tile except a calendar resource, which you can't improve. You will be able to see the edges of that tile, so you can scout around it.
In the screenshot below, we see there's a forest 4NE. It might contain a calendar resource, but since we see it at turn 50, we can arc around it.
-Huts, you should probably alter your philosophy to maximize tile vision at the cost of thoroughly scouting your adjacent lands. Hills are your friend, jungle not so much.
-Jungle areas tend to be thick and unusable early, so save it for your second or third scout.
Scouting is important. Many are people are inefficient. Hence, some algorithms that maximize the scouted area per turn.
Mechanics
A reference which explains later algorithms.
A unit sees all adjacent tiles. Screenshot unnecessary. And thanks for reminding me you can see hills one extra tile away. Sentry units will see them 3 tiles away.
A unit sees two tiles in every direction across water (including lakes), if the line of sight is not blocked. That will be explained in the land example. If a piece of land is across one tile of water, you will see it.
On a hill, you will see two tiles in every direction if not blocked by line of sight. This does not combine with the water line of site, so you will not see 3 water tiles when on top of a hill. You will see 3 with sentry, but I won't talk about that.
This screenshot shows all necessary examples of line of sight. Notice there is a hill 1 east (1E), so we can't see the tile 2 east (2E).
There is another hill 1SE, so we can't see 2SE. You can see it's a forest, but I'm not going to talk about that.
We CAN see the cow 1N2E even though there is a hill 1E, so we can see around. The LINE is not directly blocked, so we can see it.
In contrast, we can't see 1S2E since it is blocked by those two hills. There is no tile halfway in between, so we'd think we could sneak a peak between the two hills, but they form a complete seal to our line of site.
Finally, there is a forest 1N which blocks our vision of the tile 2N (I moved the scout, so we had vision, but it is in the fog). Forests and jungles block just like hills.
So remember: line of sight, forests and jungle and hills block line of sight.
And finally, diagonals are your friend! Assuming you can only see adjacent tiles, moving 1E will reveal the tiles 1N2E, 2E, 1S2E. If you move NE, you will reveal 2N, 2N1E, 2N2E, 1N2E, 2E. 5 tiles > 3 tiles.
Add screenshot.
Algorithms
The most common inefficient scouting pattern is on the coasts. Here's a dotmap of a corner tile on a coast. Note that cities cannot use the tile 2SW of our helicopter.
Hence there is no point scouting it, at least for scouting city locations.
It is sufficient to scout spot #1 above, which will reveal 1SW, 1S, 1SE, et cetera, 2S1W, 2S, 2S1E, et cetera
along with spot #1 below, which basically covers the eastern tiles.
So if you're scouting the coastline, instead of heading to a corner then moving up, save a turn of scouting by moving to the tile just before, then heading diagonally up.
Due to the map generator's jagged coastlines, this ends up saving a lot of turns.
In the above screenshot, we fully reveal all usable coastal tiles in 5 turns. Whereas if we moved to each corner, it would either take twice as long (10 turns) or we would miss the inner land tiles.
Another example, common in some windy fractal maps.
3 moves is all we need. If we scouted the corners, it would take 5-6 moves.
Sweep arcs and reveal as much as possible
*Under construction
Zigzag scouting
So often backtracking your arc leads you on a fairly straight line. You could just scout a straight line. Or, since moving diagonally takes the same amount of unit moves as moving straight, you get extra scouting by zig zagging 2 tiles back and forth in a direction.
Here's the simplest example: a straight coastline. If we hug the coastline, we only reveal 2 tiles inward from the coastline. Do that for 8 tiles and we've revealed 16 land tiles in 8 turns, along with the sea tiles.
However, if we zig zag 2 tiles in and back, we reveal 3 to 4 tiles in. Note that because of the 2 tile water property, we don't miss any coastal tiles from the first screenshot. A straight line gives us redundant coastal information.
Actually you don't need a coastline, it works with any straight corridor
We can further improve on this by adding a straight line to our zig zags.
Now we always reveal 4 tiles in, which is twice as good as our straight line scout. You cannot do this if you're doing a pure land scout, you will miss the tiles opposite of your line portions If you're curious, mentally check to sea if it grabs all the land and sea tiles.
We can combine the zig zags with the straight lines to gain more scouting. Of course, we can omit some of the straight lines to include more hills for extra vision.
If we do two straight tile moves, we will miss the other side of the zig zag, so be careful.
Of course, you aren't always aware of how far the coastline will remain straight. Moving to 1 in the picture will reveal the water 1N of the deer, and it will also indicate whether the coastline curves in, out, or stays straight to the east of the deer.
You might end up only doing a 1 tile zig zag to anticipate a curving coast (so we can do the corner trick). The zig zag with the straight line will not anticipate the coast curving away, while a pure zig zag will.
You can add zig zags to reveal more territory, but also to get better defensive terrain while not losing any coastal information.
I'll have to include more screenshots on anticipating the coast.
Here we react to the contours. If we saw a straight portion (pretend we started 1S or 1E), a zigzag would be fine if the land moved away (east to west), or lose us at most 1 turn if the land curved inland (south to north).
Planning your arcs
Under construction.
Remember it will take quite a few turns to sweep out an arc and cover another return arc. If you're too ambitious, you may not end up scouting that peninsula on the other side of your city. So consider scouting it first and start curving around.
You start with a scouting unit, which will cover most major arcs. You will often build another unit before you build a settler, and sometimes it will have time to cover smaller arcs in the opposite direction.
Tips
-Coastal resources aren't as valuable early since you have to build workboats for them, so for your first arc around your city, feel free to ignore them. Your next few arcs, scout along them to find neighbors and establish the limits of your arcs.
-Animals spawn at turn 5. They won't spawn within two tiles of your scouting unit, so you have a few more turns. After that, scouts especially are vulnerable on open ground since they effectively get a lower difficulty bonus to animals. So be extra aggressive on scouting those open areas those safe turns, so you can scout safer, forested/hilled areas later.
-Once you've scouted city locations, you can scout those corners to check for islands. Check the tile yields to see if what you expect to be ocean tiles are coastal tiles.
-Your city gets site of every tile within your culture. So remember your first border pop get 2 tile vision from hills in your outer borders, meaning you can scout around it and reveal more tiles instead.
-Your second border pop won't be in time for your second city, and the tiles they reveal could be important. However, as long as huts aren't on, a non-tundra forested tile on most maps will not have a special tile except a calendar resource, which you can't improve. You will be able to see the edges of that tile, so you can scout around it.
In the screenshot below, we see there's a forest 4NE. It might contain a calendar resource, but since we see it at turn 50, we can arc around it.
-Huts, you should probably alter your philosophy to maximize tile vision at the cost of thoroughly scouting your adjacent lands. Hills are your friend, jungle not so much.
-Jungle areas tend to be thick and unusable early, so save it for your second or third scout.
