ASL Learn Advanced Squad Leader

ASL 101: LASL 101: LEARNINGEARNING

AADVANCED DVANCED SSQUADQUAD LLEADEREADER

Session 4: Line of SightSession 4: Line of Sight

with Russ Giffordwith Russ Gifford

ASL 101:ASL 101: Line of SightLine of Sight

With this module, we’ll cover ‘line of sight’ (LOS). You With this module, we’ll cover ‘line of sight’ (LOS). You will become familiar with:will become familiar with:

• What terrain blocks line of sight (What terrain blocks line of sight (obstaclesobstacles))

• How hindrances affect LOSHow hindrances affect LOS

• Understanding inherent terrainUnderstanding inherent terrain

• How buildings, hills and blind spots work in ASLHow buildings, hills and blind spots work in ASL

Goals for this ModuleGoals for this Module


To shoot at To shoot at anything in anything in

ASL, you have ASL, you have to be able to to be able to

see the target! see the target! This is called a This is called a ‘line of sight.’‘line of sight.’

Line of Sight


““Line of sight” (LOS) means the direct line that Line of sight” (LOS) means the direct line that connects the center of the hex of the sighting unit to connects the center of the hex of the sighting unit to the center of the hex of the target. Any terrain that the center of the hex of the target. Any terrain that

the line touches must be evaluated as an obstacle - a the line touches must be evaluated as an obstacle - a potential block!potential block!

Line of Sight


Very Important Point!Very Important Point!

Players may NOT stretch a LOS string EXCEPT to Players may NOT stretch a LOS string EXCEPT to check a DECLARED shot!check a DECLARED shot!

Meaning, if you check for LOS, you will take the Meaning, if you check for LOS, you will take the shot even if you do not have LOS!shot even if you do not have LOS!

Line of Sight


Stretch a sting Stretch a sting from the center from the center

dot to center dot to center dot – if it dot – if it touches a touches a

terrain that terrain that blocks, then blocks, then there is NO there is NO

LOS.LOS.

Line of Sight

Blocked by the woods!

ASL 101: Line of SightASL 101: Line of Sight

Each type of terrain, Each type of terrain, and each type of unit and each type of unit

in ASL is on this in ASL is on this chart!chart!

Line of Sight


• Terrain may Terrain may blockblock or or hinderhinder the LOS the LOS

• Blocking terrain is listed as an Blocking terrain is listed as an obstacleobstacle, along , along with the with the heightheight of the obstacle. of the obstacle.

• If at least one of the units is at a If at least one of the units is at a height greater height greater than the height of the obstacle,than the height of the obstacle, the LOS may be the LOS may be clear. (This is called a clear. (This is called a height advantageheight advantage.) .)

Line of Sight


Things this chart tells Things this chart tells us:us:

Not an obstacleNot an obstacle

Hinders LOS, but Hinders LOS, but does NOT blockdoes NOT block

Height of obstacle Height of obstacle

Line of Sight


Check this columnCheck this column

Line of Sight



And the terrain in And the terrain in questionquestion

Line of Sight



And the terrain in And the terrain in questionquestion

And see the result.And see the result.

Line of Sight


• Woods, single hex buildings and level 1 hills Woods, single hex buildings and level 1 hills are aare a level-one LOS level-one LOS obstacleobstacle. (. (blockblock))

• Hedges and walls are aHedges and walls are a half-level LOS half-level LOS obstacle.obstacle.

• Multihex buildings Multihex buildings without a stairwell symbolwithout a stairwell symbol are are 1 ½ level LOS 1 ½ level LOS obstacle.obstacle.

• Buildings Buildings withwith a stairwell symbol are a a stairwell symbol are a level-two level-two LOS LOS obstacleobstacle..

Line of Sight Rules


What is this? What is this?

Line of Sight


The black box on this chart tells us the terrain is The black box on this chart tells us the terrain is inherent terraininherent terrain, meaning it takes up the entire , meaning it takes up the entire hex. hex.

If the LOS touches any part of this hex, even just a If the LOS touches any part of this hex, even just a shared hex spine, it is touching the shared hex spine, it is touching the terrainterrain and the and the hindrancehindrance applies. applies.

Line of Sight Rules


How many single hex How many single hex buildings (bldg) can buildings (bldg) can

you see? you see?

How many are How many are wooden? wooden?

How many are stone? How many are stone?

What level obstacle What level obstacle do they represent?do they represent?

Line of Sight QuizLine of Sight Quiz


How many multi-hex How many multi-hex buildings (bldg) can buildings (bldg) can

you see?you see?

What level block do What level block do they represent?they represent?



See any examples of See any examples of inherentinherent terrain on terrain on

this board?this board?

Just one – Just one – graingrain



We can see INTO We can see INTO a hex with a hex with

blocking terrain, blocking terrain, but not PAST it.but not PAST it.

Unless we have a Unless we have a height advantage!height advantage!

Line of SightLine of Sight


We can see INTO We can see INTO a hex X3, a hex X3,

but not PAST it but not PAST it to hex Y4.to hex Y4.

(The building in (The building in X3 is a 1 level X3 is a 1 level

obstacle. We are obstacle. We are at level 0.) at level 0.)

Line of Sight Line of Sight


We can see INTO We can see INTO the woods in hex the woods in hex

X1, X1, but not PAST it but not PAST it

to hex Y1.to hex Y1.

(The woods in (The woods in X1 is blocking X1 is blocking

terrain.)terrain.)



We can see INTO We can see INTO the woods in hex the woods in hex

W4, W4, but not PAST it.but not PAST it.

(The woods in (The woods in X1 is blocking X1 is blocking

terrain – and so is terrain – and so is the hill.)the hill.)



What about the What about the hedge on the hedge on the

W3/X2 hexside? W3/X2 hexside?



Hexside obstacles Hexside obstacles are much like in are much like in

hex terrain:hex terrain:

If we touch it, If we touch it, we can see INTO we can see INTO the hex, but not the hex, but not

PAST it. PAST it.



So, the hedge So, the hedge blocks LOS from blocks LOS from V2 to Y3. Why?V2 to Y3. Why?



So, the hedge So, the hedge blocks LOS from blocks LOS from V2 to Y3. Why?V2 to Y3. Why?

Because the Because the attacker and attacker and target are on target are on

Level 0, and the Level 0, and the wall is a ½ level wall is a ½ level

obstacle.obstacle.



What about the What about the LOS from V2 to LOS from V2 to

Y2?Y2?



What about the What about the LOS from V2 to LOS from V2 to

Y2?Y2?

Clear!Clear!

The LOS does The LOS does notnot cross the cross the

hedge.hedge.



Special note on Special note on Hexside Hexside

obstacles:obstacles:

LOS touches the LOS touches the terrain if it terrain if it

touches a vertex. touches a vertex.



Other differences Other differences with hexside with hexside

terrain:terrain:

This LOS crosses This LOS crosses the hedge. Is the the hedge. Is the LOS from W4 to LOS from W4 to

X1 blocked?X1 blocked?



Clear!Clear!

Why?Why?



The MMC is on a The MMC is on a hill, at level one. hill, at level one.

The hedge is only The hedge is only a ½ level block a ½ level block

located on a level located on a level zero hex – total zero hex – total

block height is ½ block height is ½ level.level.


MMC MMC located at located at Level 1Level 1


Since the MMC is Since the MMC is hirer than the hirer than the

blocking terrain, blocking terrain, (Lvl 1 > Lvl ½) (Lvl 1 > Lvl ½) the 467 can see the 467 can see overover the hedge. the hedge.


MMC MMC located at located at Level 1Level 1


Another important point: Another important point:

LOS in ASL is LOS in ASL is reciprocalreciprocal – –

if you can see the target, the target can see you!if you can see the target, the target can see you!

Line of Sight


What about the LOS What about the LOS from W4 to X2?from W4 to X2?

The height of W4 The height of W4 allows them to see allows them to see

over it, but -- over it, but --

the hedge still gives a the hedge still gives a unit in X2 a +1 TEM.unit in X2 a +1 TEM.



What about the What about the LOS from W4 to LOS from W4 to

Y3?Y3?



What about the What about the LOS from W4 to LOS from W4 to

Y3?Y3?

Blocked! Blocked!

Why? Why?



The height of W4 The height of W4 is Level 1 – is Level 1 –

and so is the and so is the block height of block height of the building. the building.

Can see past it, Can see past it, but need to be but need to be

HIGHER to see HIGHER to see to the ground.to the ground.



What about from What about from W5 to Y2?W5 to Y2?



What about from What about from W5 to Y2?W5 to Y2?

Clear!Clear!

Why?Why?



The height of W5 The height of W5 is Level 2 – is Level 2 –

and the block and the block height of the height of the

building is only building is only level 1. level 1.

Lvl 2 > Lvl 1Lvl 2 > Lvl 1



What about W5 What about W5 to W1?to W1?

Blocked!Blocked!

Why?Why?



While the Woods While the Woods in W4 is only a in W4 is only a

Level 1 block – it Level 1 block – it is ON Level 1, so is ON Level 1, so

it has an actual it has an actual height of Level 2.height of Level 2.

And that’s the And that’s the same height as same height as

W5.W5.



What about W5 What about W5 to Y3?to Y3?

It looks clear – It looks clear – because terrain is because terrain is only considered only considered

in the LOS if in the LOS if terrain is visible terrain is visible on both sides of on both sides of the LOS string!the LOS string!



If it were If it were touching the touching the

building, it would building, it would be blocked. be blocked.

Why? Why?



Blind Hexes:Blind Hexes:

Obstacles create Obstacles create potentialpotential blind hexes at the base blind hexes at the base level behind them equal to their full level height level behind them equal to their full level height

(FRD)(FRD)

Thus: Thus:

• 1 hex blind spot behind a level 1 obstacle.1 hex blind spot behind a level 1 obstacle.

• 2 blind hexes behind a level 2 obstacle, etc. 2 blind hexes behind a level 2 obstacle, etc.




A unit in V4:A unit in V4:

Can it seeCan it see

T1? T2? T1? T2?

V2? V1? V2? V1?

What about U1?What about U1?

Those should all Those should all be easy.be easy.



A unit in V4 is at A unit in V4 is at lvl 1, so draw lvl 1, so draw

your lines.your lines.

T1 and T2 are T1 and T2 are easy – yes.easy – yes.

V1 and V2 are V1 and V2 are also easy – no.also easy – no.

What about U1? What about U1?




Can it see U6?Can it see U6?

Both levels, Both levels, right? right?

What about R3? What about R3?

Both levels?Both levels?

What about S3?What about S3?


We are only at lvl 1, and the T3 bldg is a lvl 1 We are only at lvl 1, and the T3 bldg is a lvl 1 obstacle – so we can’t see to the ground. obstacle – so we can’t see to the ground.

We say S3 has a blind hex at the lower level We say S3 has a blind hex at the lower level because of the lvl 1 bldg in T3.because of the lvl 1 bldg in T3.

But since we are at lvl 1, we can see over the top But since we are at lvl 1, we can see over the top of a lvl 1 block to see anything at the same level.of a lvl 1 block to see anything at the same level.

So we can see the lvl 1 location in S3.So we can see the lvl 1 location in S3.




On level 1 to On level 1 to level 1 is clear if level 1 is clear if nothing higher is nothing higher is

in between.in between.




What about LOS What about LOS to T6?to T6?




Looking at T6, Looking at T6, we draw the line.we draw the line.

It cuts the corner It cuts the corner of U6, so we of U6, so we cannot see cannot see

EITHER level of EITHER level of T6. T6.



Now, move the Now, move the unit to U7:unit to U7:

Still at lvl 1, and Still at lvl 1, and it can see both it can see both lvls of T6 and lvls of T6 and

U6. U6.

We cannot see T5 We cannot see T5 or U5 – but can or U5 – but can

see R5 lvl 1? see R5 lvl 1?



From U7:From U7:

Still at lvl 1, but Still at lvl 1, but we cannot see the we cannot see the

Lvl 1 locations Lvl 1 locations past T5 and U5 past T5 and U5 because a multi-because a multi-hex bldg with no hex bldg with no inherent stairwell inherent stairwell

is a lvl 1 ½ is a lvl 1 ½ block! block!



Now - a unit in Now - a unit in W5:W5:


U2? U2?

R3? Both levels? R3? Both levels?

What about R7?What about R7?

Those should all Those should all be easy now.be easy now.


Blind Hexes vary:Blind Hexes vary:

Obstacles create Obstacles create potentialpotential blind hexes behind blind hexes behind them equal to their full level height (FRD)them equal to their full level height (FRD)

Potential, because a height advantage will reduce Potential, because a height advantage will reduce the number of blind hexes by one for each full the number of blind hexes by one for each full level of height advantage beyond the minimum level of height advantage beyond the minimum to see past the unit. to see past the unit.



However: However:

Blind Hexes:Blind Hexes:

Potential Blind hexes Potential Blind hexes increaseincrease by one for each by one for each multiple of 5 hexes in range (FRD). multiple of 5 hexes in range (FRD).

So – at 1 to 5 hexes, blind hexes as per height.So – at 1 to 5 hexes, blind hexes as per height.

6 to 10 hexes – blind hexes increase by one hex.6 to 10 hexes – blind hexes increase by one hex.

11-15 – blind hexes increased by 2 hexes. 11-15 – blind hexes increased by 2 hexes.



OK – so what OK – so what about hills and about hills and

blind hexes. Look blind hexes. Look at W5 to Y4? at W5 to Y4?

Is there a 1 hex Is there a 1 hex blind spot behind blind spot behind the level 1 hill? the level 1 hill?



Is there a 1 hex Is there a 1 hex blind spot behind blind spot behind the level 1 hill? the level 1 hill?

No. Hills only No. Hills only create their first create their first

blind hex at blind hex at distances greater distances greater than 5 hexes. than 5 hexes.






U6? Both levels? U6? Both levels?

T6? Either level?T6? Either level?

What about S7?What about S7?




U6: Yes. U6: Yes. Continuous Continuous

slope. slope.

T6: No. Can’t see T6: No. Can’t see through roof!through roof!

S7: Blind hex!S7: Blind hex!



Last question: Last question: Unit in W7:Unit in W7:

Can it see R5? If Can it see R5? If yes, which yes, which

levels?levels?



W7: Lvl 2W7: Lvl 2

T6: Lvl 1 ½T6: Lvl 1 ½

Lvl 2 > Lvl 1 ½Lvl 2 > Lvl 1 ½

Blind hexes - FRD Blind hexes - FRD

S6: blind.S6: blind.

R5: Clear! (both R5: Clear! (both levels)levels)



Last question: Last question: Unit in W7:Unit in W7:

Can it see R6?Can it see R6?

If yes, which If yes, which levels?levels?

If no, why not?If no, why not?



W7: Lvl 2W7: Lvl 2

U7: Lvl 1 + Lvl 1 U7: Lvl 1 + Lvl 1 woods = Lvl 2woods = Lvl 2

No height No height advantage means advantage means

no LOSno LOS


Note: Note: Sometimes in Sometimes in ASL, the LOS ASL, the LOS is drawn to a is drawn to a

vertex vertex ((bypassbypass) or a ) or a hexsidehexside ( (snap snap

shot, road shot, road movementmovement))

Line of Sight


Does Brush block Does Brush block LOS?LOS?

Line of Sight


Does Brush Block Does Brush Block LOS?LOS?

No – it is a No – it is a hindrance.hindrance.

Line of Sight


Some terrain does NOT block LOS, but hinders Some terrain does NOT block LOS, but hinders it by adding a +1 modifit by adding a +1 modifier to the attack, or for ier to the attack, or for sighting: sighting:

Which ones?Which ones?

HindranceHindrance


Some terrain does NOT block LOS, but hinders Some terrain does NOT block LOS, but hinders it by adding a +1 modifier to the attack, or for it by adding a +1 modifier to the attack, or for sighting.sighting.

BrushBrush and and graingrain hinder LOS by adding +1 if it is hinder LOS by adding +1 if it is on the same level as the target and the firing on the same level as the target and the firing unit.unit.

HindranceHindrance


Smoke and Dust also hinder LOS, as do Smoke and Dust also hinder LOS, as do orchards, vineyards, crags. orchards, vineyards, crags.

These types hinder LOS even between units not These types hinder LOS even between units not on the same level.on the same level.

HindranceHindrance


Note: Different types of smoke offers different Note: Different types of smoke offers different hindrances. (+1, +2, +3, etc.)hindrances. (+1, +2, +3, etc.)

Also, smoke adds an additional +1 to anyone Also, smoke adds an additional +1 to anyone firing OUT of a smoke hex!firing OUT of a smoke hex!

HindranceHindrance


Last quiz – which terrain types are Last quiz – which terrain types are inherentinherent? ?

Also note that some counter-noted items are also Also note that some counter-noted items are also inherent – the main ones are smoke and inherent – the main ones are smoke and vehicle wrecks. vehicle wrecks.



For further information: For further information: Read Read Section A6.0 Section A6.0 (all) , (all) ,

B .1 to .10B .1 to .10, and, andthe Terrain Effects dividerthe Terrain Effects divider in in

in the rule book for in the rule book for

AADVANCED DVANCED SSQUAD QUAD LLEADEREADER..

For Further InformationFor Further Information


Now that you’ve learned how to spot the enemy, Now that you’ve learned how to spot the enemy, it is time for some target practice!it is time for some target practice!

I suggest you read section 7.0 for prep, and then I suggest you read section 7.0 for prep, and then report back for live fire practice!report back for live fire practice!

Coming Next SessionComing Next Session


In the next module, we’ll get you fired up as we In the next module, we’ll get you fired up as we take target practice with MMCs and SW!take target practice with MMCs and SW!

See you at See you at

Session 5 – Fire Combat!Session 5 – Fire Combat!

Coming Next SessionComing Next Session

ASL 101ASL 101 was created by: was created by:

• Russell Gifford Learning the Great Battles of the American Civil War(CD Rom learning series, 2005)

Mass Media and Big Government (Multi-media lecture series, 2006)

Spectacular Voyage: Lewis and Clark in Iowa, Nebraska and South Dakota (2002)

Additional InformationAdditional Information

Advanced Squad Leader, ASL, and all artwork © MMP, 2007

This Presentation is

© 2007 by Russell Gifford

May be used with permission

Write to [email protected]

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