One might think that a guide about trees is not needed. After all, what more could be said than trees provide wood?

I beg to differ. There is much more to know about the trees in Stronghold Crusader HD.

In this guide, we are going to branch (ha!) into several interesting topics about trees:

• What kind they are
  
• Where they grow
  
• How fast they grow
  
• How fast they spread
  
• How they form stands
  
• How they can be stopped
  
• How they might die
  
• How much wood they yield
  
• What this all means

We'll even discuss desert shrubs.

The game designers in charge of coding the trees of Stronghold Crusader HD (SCHD) kept it simple.
Or did they?

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OK, you already know this, but it still needs to be said: Stronghold Crusader HD has two types of trees: palm and olive trees. And, there are four kinds of trees:


Date Palm - probably the most common palm of the area


Coconut Palm - Watch your head!


Cherry Palm - Another kind of date palm




Olive Tree - So, where are the vats of olive oil?



There were many other types of trees in the Middle East during the Middle Ages. There were cedars, junipers, figs, mulberries, thorn trees (acacia), pines and oaks to say nothing about numerous fruit trees.

In SCHD, we have two types and four kinds of trees, which are plenty.

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Here’s where the game designers had fun. They allowed the three palms to only grow on the green farmland grasses and the olive tree to grow almost everywhere else. Here is how the four trees compare:


























There are places a tree cannot grow. No trees grow on:

• rocks
  
• water
  
• marsh
  
• oil pits
  
• stone block
  
• a ruin
  
• desert shrub

And once a farm is built, a tree will not spring up in the middle of it.

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That's the fancy word for saying trees reproduce themselves. 🌴= 🌴🌴🌴

In the real world, trees regenerate by producing seeds and then letting the seeds disperse all around them. Some of the seeds germinate into sprouts, regenerating the tree. The game simulates this. It lets the palms and olive trees regenerate. They spread across the map, steadily and silently, almost eagerly in Stronghold Crusader HD.

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Every regenerated tree in SCHD begins as a sprout and grows through four stages to maturity:

1. sprout - a tiny sprig
   
2. sapling - a larger sprig
   
3. pole - a shorter version of a mature tree
   
4. mature - a full grown tree capable of producing seed and sprouts

This is how the coconut palm looks in all four stages:


The time it takes to grow from a sprout to a mature tree varies by the kind of tree (and varies slightly for each tree of the same kind):
....> About 3 Years: Cherry Palm
....> About 3 1/2 Years: Olive Tree and Coconut Palm
....> About 4 Years: Date Palm

(Coconut palm can vary from 3 years to 4 years.)

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Do the four kinds of trees in SCHD regenerate at the same rate (same rate of spread)?

No. And this is important.

The fastest spreading tree is the pudgy cherry palm. It out paces all the other trees. There is not a close second.


The cherry palm takes first place on both thick scrub grass and oasis grass. (It does best on thick scrub.) Recall that the cherry palm also matures faster than all other kinds of trees.

A single cherry palm will regenerate into over 55 new trees in 15 years. If left to its own devices, cherry palm would become the Greatest Lord on a map of green farm grasses.

In second place is the tall, spindly coconut palm on both oasis grass and thick scrub grass. It spreads out at about the same rate on both grasses (about 35 new trees in 15 years from a single start).

Sharing second place, sort of, is the date palm on oasis grass. The date palm spreads slightly slower than the coconut palm, but close enough to share second place.


Third place goes to the olive tree, on earth, beach and drifting sand landscapes. A single olive tree will regenerate into about 30 new trees in 15 years.

Wait, there is a tie. The date palm growing on thick scrub does just as well.

Fourth place goes to the olive tree, again, on both scrub grass and earth & stone this time, regenerating about 20-25 new trees over 15 years from a single tree.

Let me summarize this another way:

On oasis grass, the cherry palm spreads faster than any other palm (recall that olive trees do not grow on farm grasses). And, the coconut and date palms do their best regeneration on oasis grass. The coconut palm does a little better than date palm.


On thick scrub grass, the cherry palm explodes in growth, spreading faster than on oasis grass. The coconut and date palms spread well on thick scrub, but not as well as being on oasis grass (in this they differ from the cherry palm).


The olive tree spreads faster on barren land with few rocks (driven sand, beach, earth) than it does on lands with rocks and stones (scrub grass and earth & stone).

The wind in the trees adds motion to the map, nothing else. It does not help spread seeds for regeneration.

The game designers cleverly varied the speed of the wind. A constant movement of the trees would have become annoying.

The wind cycles through three phases which occur in this order: gentle breezes which rustle the tree leaves, a gust which blows hard against the trees and no wind at all (trees are still). Each cycle lasts about 3 1/2 months. In each cycle, gentle breezes occur for about 2 1/2 months (most of the time) and the gusts and no wind last about 1/2 a month each.

I could not detect that the wind played any role in tree regeneration or natural tree death. It only gave some rhythmic sway to the trees.


Q: Is there a way to speed up or slow down regeneration through game events?
A: No, although there is a tree fungus event which kills trees and by doing so reduces the density of trees. It does not change how fast the trees will spread.

Q: Is there a game event which makes trees suddenly appear on a map?
A: That would be a nice option, but there is no such event.

Q: Do apple trees ever go rogue and spread beyond the orchard?
A: No. I have never seen this.

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This section describes the game mechanics of regeneration. It falls under the category of “Probably More Than You Wanted to Know”, so feel free to skip down to the section on Barriers. Otherwise, prepare to have your mind blown.

This has already been stated, but merits repeating as a preface to this section: only a mature tree can produce sprouts. Let’s call this a parent tree.

Tree sprouts do not appear willy nilly. The game code of SCHD does not pop up a sprout just anywhere under a parent tree. They appear in a grid pattern around a parent tree.

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There are only eight spots around a parent tree in which the game code allows a new sprout to appear. This is true for all four kinds of trees.



What does this diagram show?

1. Each little square represents a space on a game map as measured by a single column of block. One column of block = one space on a map = one square in the diagram.
   
   
2. The grey squares with the little palms are the eight spots where a sprout may appear in relation to the parent tree.
   
   
3. Notice that the game code restricts sprouts to exactly four spaces along each cardinal axis and exactly six spaces along each diagonal axis from the parent tree. No closer, no further than what the code is set at.
   
   This is why a barrier of six spaces or more stops the spread of trees. A mature tree cannot cast its seed beyond six spaces (a sprout appears in the sixth space).

Here is a map view of the 8-spot grid pattern around a cherry palm parent tree. Each spot is marked by a square of earth.



In my numerous tests to force a tree to regenerate in a different pattern or with different spacing, none succeeded. The game code is strict: only eight spots at fixed spacing around each parent tree.

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At various time intervals, the game code randomly selects which of the eight spots will produce a sprout. At least one sprout will appear each year for each parent tree until the eight spots are occupied. This is not exact, but close. Sometimes two sprouts will appear in a year, and sometimes none from a parent tree. The stubby cherry palm will consistently produce two sprouts per year per parent tree until all eight spots are filled.

Through testing, I found that once only two spaces remain unoccupied in the 8-spot grid of a parent tree (the grid is 75% filled or occupied), the chance of a new sprout drops, but not drastically. Obviously, the game code searches for empty spots around each tree but not exhaustively. Grids that were filled 25% and 50% did not show any reduction in the rate of new sprouts appearing.

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Trees will maintain at least three spaces between themselves. The game code will not sprout a new tree within three spaces of another tree.

There is an exception to this rule. When trees are "pre-planted" by the map maker in an area, the game code will allow a new spout to appear within a square's distance of a pre-planted tree. I have noticed that the pre-planted tree soon dies.

The 3-space rule allows fairly large gaps in the forest. This is why an army can move through a forest without much difficulty: the trees cannot form a natural wall.

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Over time, a parent tree will try fill all eight spots around it with its offspring. This rarely happens because its offspring mature and start their own dispersal of seed in identical and overlapping 8-spot grids.

This causes a larger pattern or mosaic of trees to emerge. It is always an incomplete pattern.

The randomness of where sprouts appear in the 8-spot grids of mature trees, and the 3-space rule, combine to create a predictable yet incomplete pattern of trees.

In the image below, the red lines show where the parent tree produced a sprout, an offspring. which then matured into a full-grown tree. The other colored lines show where the matured offspring produced sprouts of their own, which also matured. A pattern of the trees begins to emerge.



I traced this larger pattern in several stands of trees. I used stone block to show the spaces between the trees and the pattern of the stand of trees. The cherry palm and coconut palm are shown below (2D flattened view).


Despite the randomness in where the sprouts appear around a parent tree and the 3-space rule between trees, a stand of trees on an open plain will form a clump and are not scattered all over the place.

The clump of trees will take on a patchy, square block pattern, as shown by this stand of date palms, but not always.



Notice how the trees form lines and how the lines are in a criss-cross. This is due to both the cardinal and diagonal axes in the 8-spot grid of where sprouts can appear, AND the restriction that new sprouts cannot be closer than three spaces to another tree.

These two game code conditions cause trees to grow in an almost orchard style pattern.

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There are two take home points in this section about patterns of tree growth.

1. Each mature tree has eight spots around it in which the game code randomly allows a sprout to appear, if the spot is unoccupied.
   
2. Trees spread across an area in a systematic way which produces a distinct and predictable pattern. Randomness along two axes and a forced 3-space interval between trees causes a patchiness to this pattern. The speed at which each kind of tree matures and the rate of regeneration, which also varies by the kind of tree, adds another distinction to the pattern.

Next, let’s talk about what stops a tree from growing.

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A barrier of six spaces of more will stop the spread of a tree. A space is measured by a single column of block on a map.

In this picture, the palm trees could jump across 5 spaces of water but not across 6 spaces.


If a stand of trees (or single tree) borders a landscape which they cannot grow on (a barrier) which stretches 6 spaces or wider, they cannot send their seed across that barrier. They cannot jump that barrier.

The spread of the tree is stopped by a barrier.

There are several elements on a map which can act as a barrier to trees:

• A river, lake or pond
  
• Rock (including stone and iron)
  
• Marsh
  
• A landscape the tree cannot grow on
  
• Stone block wall or building
  
• Ruins of a building
  
• A line of pre-built farms
  
• A desert shrub
  
• A confined area (explained below)

I often use a mix of these as shown below:


(Preserving open space around a quarry)

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This is a small area which is completely enclosed (encircled) by a map element which is a barrier to tree growth, like a stone wall or rock or water.

AND, the game code will not allow a sprout to appear if the enclosed area does not include enough room for ANOTHER sprout to later appear.

Said another way, a confined area is an area not large enough for at least two trees.

(A tree pre-planted by the map maker in a confined area will usually die in a few years.)

Here are some examples of confined areas (left side) and unconfined areas (right side) of islands, gardens and rock ledges:



Q: How do I measure spaces on a map to ensure a barrier is at least six spaces wide?
A: Use stone columns to count the spaces, then delete the columns.

Q: Does a high wall stop tree seeds from passing over it?
A: No. A tree will send its seeds over a high wall and sprouts can appear on the other side of the wall.

Q: Will a tree sprout next to a stone wall, or is there a "dead space" next to a stone wall?
A: There is not a dead space. A tree will sprout next to a stone wall.

Q: Will a tree sprout next to a stone tower or guard gate?
A: No. There IS a dead space beside a stone tower and gate. A tree will NOT sprout next to a tower or gate (or a flower garden).

Q: Will a tree sprout next to a river or lake?
A: Yes, a sprout can appear right at the water's edge (if the soil is right).

Q: Which desert shrub is a barrier to a tree sprout?
A: All of them. If a desert shrub occurs on one of the eight spots around a parent tree at which sprouts appear (see the section on Patterns of Tree Growth), a tree will not appear at that spot.

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Trees in SCHD exit the scene four different ways:

1. Chopped down for wood
   
2. Killed by a fungus
   
3. Killed by fire
   
4. Die naturally

Q: Can't a catapult or a mangonel knock down trees with stone?
A: One would think a flying stone would eventually hit a tree but it doesn't.

Let's look a little closer at the four different ways a tree can die.


It might seem that the short, fat cherry palm takes longer than all other trees for a wood chopper to chop up, but the simple truth is that all mature trees take the same number of whacks of the axe to harvest.

It takes five chops to bring down a tree. A wood chopper will whack four times to cut out a log. There are nine logs in every mature tree. Each log yields four boards of lumber.

So, every tree takes 41 whacks of the axe to both chop down and then chop up and yields 36 boards of wood (by way of three trips to the stockpile).

Sprouts, saplings, pole sized trees take fewer chops to fall and yield less wood (fewer logs).

You probably have noticed this, but a wood chopper chooses the closest tree to his hut to chop on. It is not necessarily the most convenient or most logical tree, for a wood chopper will walk past other trees on his route to the closest tree.


Don't do this unless you want to rid the map of almost all the trees.

The event driven fungus attack on trees (although a drought is blamed) instantly kills about 80% of all the trees on a map. That's four out of five trees suddenly gone. That's a heavy blow.

And, the downed trees are not good for wood. A wood chopper will walk right past the fallen trees.

And, the fallen trunks lay on the ground for years and years blocking the land from farms and buildings.

A second attack will kill 80% of all remaining trees.

If you ever evoke a fungus attack, fire is the best way to clear the fallen timber.

Interestingly, a fungus attack kills about 80% of every kind of tree, so if there are just a few olive trees but lots of date palms on your map, both will experience about 80% death.


Fire kills trees, it removes the scorched trees completely off the map. To create a forest fire, one can burn scattered pitch plots or have Arabians throw fire into the trees.

Why do this? The only reason I can think of is to clear farm land in a hurry.

Forest fires spread only a little piece and then go out, unless more fire is added.

As a point of trivia: apple trees can also be killed by fire.




The game code randomly targets trees to naturally die. Tree deaths are so infrequent and so scattered that it is almost unnoticeable.

I might be wrong, but it seems that olive trees die more often on scrub grass and earth & stone landscapes than the other landscapes.

It is not always the mature trees which die. Young trees can suddenly die as well.

If a tree is "pre-planted" by the map maker on a landscape it cannot regenerate on (a palm on barren earth for example), the tree will naturally die within a few years.

Also, if a tree is pre-planted in a confined area or later encircled by the player with block, the tree will soon die.

The stump of a naturally deceased tree lasts a few months and then rots away (disappears).

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If you don’t mind that your game map becomes overrun with an entanglement of trees, then none of this much matters.

If you wish to use trees strategically and/or aesthetically on a map, then all this matters.


Let's begin with how trees can add realism to a map.

The choice of landscaping (earth and grasses) determines the types of trees which adorn the map. You now know which landscape types support which trees. For example, you may want to use the lush oasis grass along the rivers for date palms (the slowest spreading palm), the thick scrub in the low plains for the other two palms (only a few cherry palm!) and confine the olive trees to the hill tops.

Or, you might want a desert scene in which coconut palms must be removed from grasses around an oasis to provide needed farm land and numerous olive trees (for wood) are scattered among the rock cliffs on scrub grass. A decorative barrier could be used to prevent the olive trees from spreading onto the desert sands and becoming too abundant.

The placement of barriers not only adds character to a map but secretly controls the spread of trees. There are several creative ways to make obscure barriers of mixed elements. Confining trees to areas of the map is crucial in maintaining the aesthetics of a map.

Controlling the spread of trees which decorate a pathway or border gardens in a castle is a simple matter of choosing an unsuitable landscape to limit the trees from spreading. Or, blocking the eight spots around a tree has the same effect.

Finally, blending the landscape types into each other not only adds realistic color tones to the map but also can keep the pervasive olive tree from rapidly spreading to every corner of the map or the cherry palm from becoming the Greatest Lord.


The most obvious and often used strategic element of trees is their wood.

If you want to limit wood, don’t use the short, fat cherry palms which spread faster than the wood choppers can keep up with. And watch those olive trees which spread to every piece of barren land. Use the more slower spreading, slow maturing date palms instead and confine them to an area with barriers.

You now know that all four kinds of trees yield the same amount of wood (9 logs per tree) with the same amount of effort from the wood chopper (41 chops), so there is no tactical advantage to date palms verse coconut palms verse any tree for its wood. But, again, the regeneration rate of trees comes into play with cherry palms leading the way. A stand of cherry palms will yield far more wood than a stand of coconut trees simply because the cherry palms reproduce much faster.

Trees block things, which is a great strategic ploy. Palm trees block farm land. Olive trees can block building spots around a keep, or expansion of a granary for instance. Strategically placed stands of trees can either cause the player the extra toil of clearing land or remove that toil.

Blighted trees from a fungus attack add a challenge to clearing land since wood choppers will not harvest the fallen trees and the derelict trunks linger for years. Deciding whether or not to enable fire is also a strategic choice.

Armies move through very dense woods as easily as a open plain, however, trees do block a square of land and can cause soldiers to take a more twisted route than they would on an open plain.

Interestingly, tunnelers are not bothered by trees. They will not tunnel under a tree but go around each tree as they burrow towards a castle.

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Desert shrubs are the "other" kind of vegetation on a map. They were designed for map decorations (scenery), pure and simple.

Trees regenerate, grow, spread and die. Desert shrubs never change once placed on a map, unless destroyed by fire. They do sway in the wind (except the cacti).

Interestingly, SCHD desert shrubs are not really shrubs, in the botanical sense. Here is how they sort out:



Desert shrubs do not block farms or buildings, but they can block a tree sprout from appearing and as such can be used as a barrier to trees.

If a desert shrub occupies any of the eight spots where a sprout would appear around a parent tree, a sprout would be blocked from appearing (see the section of Patterns of Tree Growth). This can be useful when trees are used in a castle or around a garden or in any special scenic location where the map maker does not want the tree to spread. Desert shrubs can be used to block some or all of the spots a sprout would appear.

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What has been said in this guide?

I’m certain that the game designers for SCHD could have made trees to be mere decorations on a map, like the desert shrubs, but they did not for a reason.

The reason, I believe, is that they wanted trees to add to the challenge and fun of a game as much as they add to the scenery.

Wisely, they kept trees simple. Only four choices, each with equal amounts of wood once chopped down.

The only two things which they added variety to were where trees could and could not grow and the rate of spread of each tree.

Those two variables provide multiple creative ways to enhance the aesthetics of a map and add to the strategy of the game.


I hope this guide has proved useful. If it has, please consider a positive rating.

Enjoy!

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