Dirty Spellcaster Tricks

In article <zQQJg.255$pe2.70@newsfe05.lga>, ranma27.RemoveThis@charter.net wrote:
>Ubiquitous wrote:
>> groves_ca.RemoveThis@yahoo.co.uk wrote:

>>>A friend of mine came up with this trick: Use Contingency and Lightning
>>>Bolt. Set the Lightning Bolt to fire straight up when someone enters
>>>the target square. Cast this combo in a 10' high corridor. When the
>>>lightning bolt triggers, it goes straight up, causing 10d6 damage (since
>>>you need to be 14th level to cast Contingency, but LB caps at 10d6).
>>>When it hits the stone ceiling, it bounces back down with 110' of length
>>>left, causing another 10d6. When it hits the stone floor, it bounces
>>>back up with 100' of length left, causing another 10d6 damage...see
>>>where this is going?
>>>
>>>Aw, heck, I'll spell it out: 120d6 damage to one target.
>>
>> Read the PH. It doesn't work that way.
>
>I do not know what version you are playing as I do not know the
>Contingency spell. Please forgive me if the Lightning Bolt spell has
>been redefined. I can however assure you, at least under 1st ed and 2nd
>ed, Lightning Bolt does bounce. I remember in the old SSI games, blue
>dragons loved to get you where they could bounce the bolts off walls.
>One breath and it might take out a party even if everyone saved. I also
>used it to kill many a creature by getting in multiple attacks with one
>spell.

I seem to recall it was rather vague in 1st edition, but in 2nd edition
it was changed so that if the bolt cannot extend(?) to its full length,
you are sppsd to extend it from the starting point (towards the caster?)
until the full length is reached.

--
It is simply breathtaking to watch the glee and abandon with which
the liberal media and the Angry Left have been attempting to turn
our military victory in Iraq into a second Vietnam quagmire. Too bad
for them, it's failing.
 >> Stay informed about: Dirty Spellcaster Tricks 

On Thu, 14 Sep 2006 11:39:15 -0400, Ubiquitous <weberm RemoveThis @polaris.net>
wrote:

>In article <zQQJg.255$pe2.70@newsfe05.lga>, ranma27 RemoveThis @charter.net wrote:
>>Ubiquitous wrote:
>>> groves_ca RemoveThis @yahoo.co.uk wrote:
>
>>>>A friend of mine came up with this trick: Use Contingency and Lightning
>>>>Bolt. Set the Lightning Bolt to fire straight up when someone enters
>>>>the target square. Cast this combo in a 10' high corridor. When the
>>>>lightning bolt triggers, it goes straight up, causing 10d6 damage (since
>>>>you need to be 14th level to cast Contingency, but LB caps at 10d6).
>>>>When it hits the stone ceiling, it bounces back down with 110' of length
>>>>left, causing another 10d6. When it hits the stone floor, it bounces
>>>>back up with 100' of length left, causing another 10d6 damage...see
>>>>where this is going?
>>>>
>>>>Aw, heck, I'll spell it out: 120d6 damage to one target.
>>>
>>> Read the PH. It doesn't work that way.
>>
>>I do not know what version you are playing as I do not know the
>>Contingency spell. Please forgive me if the Lightning Bolt spell has
>>been redefined. I can however assure you, at least under 1st ed and 2nd
>>ed, Lightning Bolt does bounce. I remember in the old SSI games, blue
>>dragons loved to get you where they could bounce the bolts off walls.
>>One breath and it might take out a party even if everyone saved. I also
>>used it to kill many a creature by getting in multiple attacks with one
>>spell.
>
>I seem to recall it was rather vague in 1st edition, but in 2nd edition
>it was changed so that if the bolt cannot extend(?) to its full length,
>you are sppsd to extend it from the starting point (towards the caster?)
>until the full length is reached.
>


Yeah, this was a very old message - I just happened across it and
noticed no one had corrected an error.

You were correct that a LIGHTNING BOLT bounced in 1e/2e, but incorrect
in applying the damage more than once. You could not take more from a
spell by crossing it several times than you could be staying in it
continuously. Instead, the official ruling was that you had to make
an additional SAVING THROW for each time you crossed the spell. So in
your example the person would take 10d6, or half that if he made 12
saves. Fail any one of the 12 saves and he caught the bolt full-on at
least once for the full 10d6 damage. I don't recall offhand if this
was a separate article in Dragon, or a column like Sage Advice, or
just what - but it made it clear that it was the official rule.

The typical use for this was for destroying nasty evil magical things
that only failed a saving throw on a 1. Give a Magic User and put him
between 2 solid rock walls 5 feet apart. Someone else throws a
targeted DISPEL MAGIC on the thing to be destroyed and the MU casts
the LIGHTNING BOLT-BOLT-BOLT-BOLT-etc. Unless it was an Artifact, it
was very likely to fail a save. The Mage had to eat the 10d6 too, of
course. Bonuses on saves weren't much help. The only common
effective thing was if you had a Druid who could cast a PROTECTION
FROM LIGHTNING on him (cutting the damage 50%), or it was a Druid/Mage
multiclass casting the PFL on himself (for total immunity) prior to
the LIGHTNING BOLT.

As I recall, in 1e you could get "angle of incidence equals angle of
reflection" bounces and do zigzags down a corridor while in 2e it
always bounced back towards the caster even if it hit a wall at an
angle. But the "bouncing between two parallel walls" trick worked the
same in both editions.

Of course, in 3e they got rid of the bounces (dang it <g>).
 >> Stay informed about: Dirty Spellcaster Tricks 

On Sun, 30 Mar 2008 09:49:56 GMT, quester RemoveThis @infionline.net (Harold
Groot) wrote:
>On Thu, 14 Sep 2006 11:39:15 -0400, Ubiquitous <weberm RemoveThis @polaris.net>
>>In article <zQQJg.255$pe2.70@newsfe05.lga>, ranma27 RemoveThis @charter.net wrote:
>>>Ubiquitous wrote:
>>>> groves_ca RemoveThis @yahoo.co.uk wrote:
>>
>>>>>A friend of mine came up with this trick: Use Contingency and Lightning
>>>>>Bolt. Set the Lightning Bolt to fire straight up when someone enters
>>>>>the target square. Cast this combo in a 10' high corridor. When the
>>>>>lightning bolt triggers, it goes straight up, causing 10d6 damage (since
>>>>>you need to be 14th level to cast Contingency, but LB caps at 10d6).
>>>>>When it hits the stone ceiling, it bounces back down with 110' of length
>>>>>left, causing another 10d6. When it hits the stone floor, it bounces
>>>>>back up with 100' of length left, causing another 10d6 damage...see
>>>>>where this is going?
>>>>>
>>>>>Aw, heck, I'll spell it out: 120d6 damage to one target.
>>>>
>>>> Read the PH. It doesn't work that way.
>>>
>>>I do not know what version you are playing as I do not know the
>>>Contingency spell. Please forgive me if the Lightning Bolt spell has
>>>been redefined. I can however assure you, at least under 1st ed and 2nd
>>>ed, Lightning Bolt does bounce. I remember in the old SSI games, blue
>>>dragons loved to get you where they could bounce the bolts off walls.
>>>One breath and it might take out a party even if everyone saved. I also
>>>used it to kill many a creature by getting in multiple attacks with one
>>>spell.
>>
>>I seem to recall it was rather vague in 1st edition, but in 2nd edition
>>it was changed so that if the bolt cannot extend(?) to its full length,
>>you are sppsd to extend it from the starting point (towards the caster?)
>>until the full length is reached.
>
>Yeah, this was a very old message - I just happened across it and
>noticed no one had corrected an error.
>
>You were correct that a LIGHTNING BOLT bounced in 1e/2e, but incorrect
>in applying the damage more than once. You could not take more from a
>spell by crossing it several times than you could be staying in it
>continuously. Instead, the official ruling was that you had to make
>an additional SAVING THROW for each time you crossed the spell. So in
>your example the person would take 10d6, or half that if he made 12
>saves. Fail any one of the 12 saves and he caught the bolt full-on at
>least once for the full 10d6 damage. I don't recall offhand if this
>was a separate article in Dragon, or a column like Sage Advice, or
>just what - but it made it clear that it was the official rule.
>
>The typical use for this was for destroying nasty evil magical things
>that only failed a saving throw on a 1. Give a Magic User and put him
>between 2 solid rock walls 5 feet apart. Someone else throws a
>targeted DISPEL MAGIC on the thing to be destroyed and the MU casts
>the LIGHTNING BOLT-BOLT-BOLT-BOLT-etc. Unless it was an Artifact, it
>was very likely to fail a save. The Mage had to eat the 10d6 too, of
>course. Bonuses on saves weren't much help. The only common
>effective thing was if you had a Druid who could cast a PROTECTION
>FROM LIGHTNING on him (cutting the damage 50%), or it was a Druid/Mage
>multiclass casting the PFL on himself (for total immunity) prior to
>the LIGHTNING BOLT.
>
>As I recall, in 1e you could get "angle of incidence equals angle of
>reflection" bounces and do zigzags down a corridor while in 2e it
>always bounced back towards the caster even if it hit a wall at an
>angle. But the "bouncing between two parallel walls" trick worked the
>same in both editions.
>
>Of course, in 3e they got rid of the bounces (dang it <g>).

The really funny thing is, it never did work that way in 1st ed.

I horrified a couple of players (and killed a character) by proving
it.

Here's a quote, from the AD&D PHB, page 74:

If the full length of the stroke is not possible due to the
interposition of a non-conducting barrier (such as a stone wall), the
lightning bolt will double and rebound towards its caster, its length
being the normal total from beginning to end of stroke, damage caused
to interposing barriers notwithstanding. Example: An 8" stroke is
begun at a range of 4", but the possible space in the desired
direction is only 3 1/2"; so the bolt begins at the 3 1/2" maximum,
and it rebounds 8" in the direction of its creator.

Now, here's the relevant section for AD&D2, page 151:

If a bolt cannot reach its full length, because of an unyielding
barrier (such as a stone wall), the lightning bolt rebounds from the
barrier toward its caster, ending only when it reaches its full
length.
Example: An 80-foot-long stroke is begun at a range of 40 feet, but
it hits a stone wall at 50 feet. The bolt travels 10 feet, hits the
wall, and rebounds for 70 feet back toward its creator (who is only 50
feet from the wall, and so is caught in his own lightning bolt!).

AD&D2 was also the one that *optionally* allowed bolts that reflected
off surfaces to, for example, send them around corners.


How the AD&D 1 version works:

I start the bolt at 40 feet, intending it to be an 80 foot bolt that
blows through the wall. It hits a wall at 75 feet (from me; the
bolt's gone 35 feet so far). Unfortunately, the wall is more than a
foot thick, and the bolt can't blow through. So, *starting from the
wall* at 75 feet, the bolt extends *backwards* the full 80 foot
length. I just toasted myself.

Note the important part, there. If the bolt can't blow through, you
start *from the barrier* and proceed backwards *the full length of the
bolt*. It says so right in the example I quoted.

And the AD&D 2 version:

They modified the rule to fold the bolt, because people found it too
complicated to figure the full length of the bolt from the impact
point. So, in AD&D 2, the distance from 40 to 75 gets bolted, then
the bolt hits the wall and turns around, 75 to 40 gets another bunch
of electricity, then 40 to 30 gets charged. I'm safe.



The problem with the AD&D 1 description was this bit: "... will
double and rebound...". The example clearly laid out that it didn't
do that. It started at its impact point and it went the full distance
backwards: "... begins at the 3 1/2" maximum and it rebounds 8" in
the direction...". The "rebound" was the fact that it went the wrong
way, not that it reflected and covered any portion of the distance
twice.

Basically, in AD&D 1, you took an 8" stick and put it down at the
start point of the stroke. If it hit a barrier that it couldn't blow
through, you moved the stick backwards until the end of it touched the
impact point. Everything under the stick, sometimes including the
caster, got fried.

AD&D 1 didn't cover having less than the bolt's length of distance
available. Thus, whether it would rebound again from the wall behind
the wizard or not was up to the DM. Me, I ruled "no". In AD&D 2 I
ruled "yes" because they specifically said it would do so.
 >> Stay informed about: Dirty Spellcaster Tricks 

On Thu, 03 Apr 2008 01:45:46 GMT, gobble.TakeThisOut@degook.com (Ken Andrews)
wrote:

>On Sun, 30 Mar 2008 09:49:56 GMT, quester.TakeThisOut@infionline.net (Harold
>Groot) wrote:
>>On Thu, 14 Sep 2006 11:39:15 -0400, Ubiquitous <weberm.TakeThisOut@polaris.net>
>>>In article <zQQJg.255$pe2.70@newsfe05.lga>, ranma27.TakeThisOut@charter.net wrote:
>>>>Ubiquitous wrote:
>>>>> groves_ca.TakeThisOut@yahoo.co.uk wrote:
>>>
>>>>>>A friend of mine came up with this trick: Use Contingency and Lightning
>>>>>>Bolt. Set the Lightning Bolt to fire straight up when someone enters
>>>>>>the target square. Cast this combo in a 10' high corridor. When the
>>>>>>lightning bolt triggers, it goes straight up, causing 10d6 damage (since
>>>>>>you need to be 14th level to cast Contingency, but LB caps at 10d6).
>>>>>>When it hits the stone ceiling, it bounces back down with 110' of length
>>>>>>left, causing another 10d6. When it hits the stone floor, it bounces
>>>>>>back up with 100' of length left, causing another 10d6 damage...see
>>>>>>where this is going?
>>>>>>
>>>>>>Aw, heck, I'll spell it out: 120d6 damage to one target.
>>>>>
>>>>> Read the PH. It doesn't work that way.
>>>>
>>>>I do not know what version you are playing as I do not know the
>>>>Contingency spell. Please forgive me if the Lightning Bolt spell has
>>>>been redefined. I can however assure you, at least under 1st ed and 2nd
>>>>ed, Lightning Bolt does bounce. I remember in the old SSI games, blue
>>>>dragons loved to get you where they could bounce the bolts off walls.
>>>>One breath and it might take out a party even if everyone saved. I also
>>>>used it to kill many a creature by getting in multiple attacks with one
>>>>spell.
>>>
>>>I seem to recall it was rather vague in 1st edition, but in 2nd edition
>>>it was changed so that if the bolt cannot extend(?) to its full length,
>>>you are sppsd to extend it from the starting point (towards the caster?)
>>>until the full length is reached.
>>
>>Yeah, this was a very old message - I just happened across it and
>>noticed no one had corrected an error.
>>
>>You were correct that a LIGHTNING BOLT bounced in 1e/2e, but incorrect
>>in applying the damage more than once. You could not take more from a
>>spell by crossing it several times than you could be staying in it
>>continuously. Instead, the official ruling was that you had to make
>>an additional SAVING THROW for each time you crossed the spell. So in
>>your example the person would take 10d6, or half that if he made 12
>>saves. Fail any one of the 12 saves and he caught the bolt full-on at
>>least once for the full 10d6 damage. I don't recall offhand if this
>>was a separate article in Dragon, or a column like Sage Advice, or
>>just what - but it made it clear that it was the official rule.
>>
>>The typical use for this was for destroying nasty evil magical things
>>that only failed a saving throw on a 1. Give a Magic User and put him
>>between 2 solid rock walls 5 feet apart. Someone else throws a
>>targeted DISPEL MAGIC on the thing to be destroyed and the MU casts
>>the LIGHTNING BOLT-BOLT-BOLT-BOLT-etc. Unless it was an Artifact, it
>>was very likely to fail a save. The Mage had to eat the 10d6 too, of
>>course. Bonuses on saves weren't much help. The only common
>>effective thing was if you had a Druid who could cast a PROTECTION
>>FROM LIGHTNING on him (cutting the damage 50%), or it was a Druid/Mage
>>multiclass casting the PFL on himself (for total immunity) prior to
>>the LIGHTNING BOLT.
>>
>>As I recall, in 1e you could get "angle of incidence equals angle of
>>reflection" bounces and do zigzags down a corridor while in 2e it
>>always bounced back towards the caster even if it hit a wall at an
>>angle. But the "bouncing between two parallel walls" trick worked the
>>same in both editions.
>>
>>Of course, in 3e they got rid of the bounces (dang it <g>).
>
>The really funny thing is, it never did work that way in 1st ed.
>
>I horrified a couple of players (and killed a character) by proving
>it.
>
>Here's a quote, from the AD&D PHB, page 74:
>
>If the full length of the stroke is not possible due to the
>interposition of a non-conducting barrier (such as a stone wall), the
>lightning bolt will double and rebound towards its caster, its length
>being the normal total from beginning to end of stroke, damage caused
>to interposing barriers notwithstanding. Example: An 8" stroke is
>begun at a range of 4", but the possible space in the desired
>direction is only 3 1/2"; so the bolt begins at the 3 1/2" maximum,
>and it rebounds 8" in the direction of its creator.
>
>Now, here's the relevant section for AD&D2, page 151:
>
>If a bolt cannot reach its full length, because of an unyielding
>barrier (such as a stone wall), the lightning bolt rebounds from the
>barrier toward its caster, ending only when it reaches its full
>length.
>Example: An 80-foot-long stroke is begun at a range of 40 feet, but
>it hits a stone wall at 50 feet. The bolt travels 10 feet, hits the
>wall, and rebounds for 70 feet back toward its creator (who is only 50
>feet from the wall, and so is caught in his own lightning bolt!).
>
>AD&D2 was also the one that *optionally* allowed bolts that reflected
>off surfaces to, for example, send them around corners.
>
>
>How the AD&D 1 version works:
>
>I start the bolt at 40 feet, intending it to be an 80 foot bolt that
>blows through the wall. It hits a wall at 75 feet (from me; the
>bolt's gone 35 feet so far). Unfortunately, the wall is more than a
>foot thick, and the bolt can't blow through. So, *starting from the
>wall* at 75 feet, the bolt extends *backwards* the full 80 foot
>length. I just toasted myself.
>
>Note the important part, there. If the bolt can't blow through, you
>start *from the barrier* and proceed backwards *the full length of the
>bolt*. It says so right in the example I quoted.

No, it doesn't say that.

It proceeds backwards the full REMAINING length of the bolt, thus
reaching it's full length. For comfirmation, take a look at the 1E
DMG on page 45. "...if a solid wall is struck, the bolt effectively
rebounds its full REMAINING distance..." (emphasis mine).

So on your example with starting the bolt at 40 feet and hitting the
wall at 75' it has used up 35' and has 45' left to head back towards
you. It fizzles out when it is still 30' away from you.


>And the AD&D 2 version:
>
>They modified the rule to fold the bolt, because people found it too
>complicated to figure the full length of the bolt from the impact
>point. So, in AD&D 2, the distance from 40 to 75 gets bolted, then
>the bolt hits the wall and turns around, 75 to 40 gets another bunch
>of electricity, then 40 to 30 gets charged. I'm safe.

Not modified at all. They may have changed the wording a bit, bringing
into the PH the specific word REMAINING that had been in the DMG, but
the actual system didn't change.


>The problem with the AD&D 1 description was this bit: "... will
>double and rebound...". The example clearly laid out that it didn't
>do that. It started at its impact point and it went the full distance
>backwards: "... begins at the 3 1/2" maximum and it rebounds 8" in
>the direction...". The "rebound" was the fact that it went the wrong
>way, not that it reflected and covered any portion of the distance
>twice.


Yes, it shows that if the STARTING POINT YOU INTENDED was past the
wall, then when the spell energies hit the wall it "starts" the bolt
length and immediately rebounds towards you the full length. If you
want it to start at 40' and there is a wall at 35', it starts at the
wall and goes 80' in your direction. The bolt gets its 80' all in one
direction in this case. That is the example in the 1E PH.

But if there is room for partial travel of the bolt in both
directions, you count the travel both ways.


>Basically, in AD&D 1, you took an 8" stick and put it down at the
>start point of the stroke. If it hit a barrier that it couldn't blow
>through, you moved the stick backwards until the end of it touched the
>impact point. Everything under the stick, sometimes including the
>caster, got fried.

You don't take a stick, you take a string. If it hits something solid
you double it back on itself. The 1E DMG says REMAINING distance.


>AD&D 1 didn't cover having less than the bolt's length of distance
>available. Thus, whether it would rebound again from the wall behind
>the wizard or not was up to the DM. Me, I ruled "no". In AD&D 2 I
>ruled "yes" because they specifically said it would do so.

Except that AD&D 1E =did= cover it because they use a string model,
not a stick model. You keep reflecting it until it has used up a
CUMULATIVE distance of the length of the stroke. If there are two
parallel walls 10' apart, to only take half damage you have to avoid
getting the full impact (make a save) on each of 8 legs of the
strokes. But the damage doesn't add - you can't take more damage than
the bolt has available for a full on (failed save) hit. It's just
more difficult to dodge when it tries to get you both coming AND
going.
 >> Stay informed about: Dirty Spellcaster Tricks 

In article <488d3b2f.25279359 DeleteThis @news.west.earthlink.net>,
quester DeleteThis @infionline.net (Harold Groot) wrote:

> >I start the bolt at 40 feet, intending it to be an 80 foot bolt that
> >blows through the wall. It hits a wall at 75 feet (from me; the
> >bolt's gone 35 feet so far). Unfortunately, the wall is more than a
> >foot thick, and the bolt can't blow through. So, *starting from the
> >wall* at 75 feet, the bolt extends *backwards* the full 80 foot
> >length. I just toasted myself.

Which is so absurd that we never played it that way. We used the rule
from the Real World (tm) that "the angle of incidence is equal to the
angle of reflection." One could only toast one's self if one hit the
wall at a perfect ninety degree angle (which did happen from time to
time, when people forgot to aim properly...).

And yes, that made bank shots possible.

Baird
 >> Stay informed about: Dirty Spellcaster Tricks 

Baird Stafford <baird RemoveThis @newstaff.com> wrote:
> In article <488d3b2f.25279359 RemoveThis @news.west.earthlink.net>,
> quester RemoveThis @infionline.net (Harold Groot) wrote:
>
>> >I start the bolt at 40 feet, intending it to be an 80 foot bolt that
>> >blows through the wall. It hits a wall at 75 feet (from me; the
>> >bolt's gone 35 feet so far). Unfortunately, the wall is more than a
>> >foot thick, and the bolt can't blow through. So, *starting from the
>> >wall* at 75 feet, the bolt extends *backwards* the full 80 foot
>> >length. I just toasted myself.
>
> Which is so absurd that we never played it that way. We used the rule
> from the Real World (tm) that "the angle of incidence is equal to the
> angle of reflection." One could only toast one's self if one hit the
> wall at a perfect ninety degree angle (which did happen from time to
> time, when people forgot to aim properly...).

Or got suckered into misjudging the range to the lights moving in the
distance... which happened to be a mirror at the end of the hall.

*cough* taught them to not take potshots at anything that moved, though,
and to instead see just what it is coming at them.


Keith
--
Keith Davies I married the moonshiner's daughter
keith.davies RemoveThis @kjdavies.org How could I go wrong?
keith.davies RemoveThis @gmail.com The moonshiner's daughter
http://www.kjdavies.org/ Put some corn in the water
And makes me liquor all night long
-- Hayseed Dixie, _Moonshiner's Daughter_
 >> Stay informed about: Dirty Spellcaster Tricks 

In article <baird-D05AE3.05235028072008 DeleteThis @news.giganews.com>, baird DeleteThis @newstaff.com
says...
>
>In article <488d3b2f.25279359 DeleteThis @news.west.earthlink.net>,
> quester DeleteThis @infionline.net (Harold Groot) wrote:
>
>> >I start the bolt at 40 feet, intending it to be an 80 foot bolt that
>> >blows through the wall. It hits a wall at 75 feet (from me; the
>> >bolt's gone 35 feet so far). Unfortunately, the wall is more than a
>> >foot thick, and the bolt can't blow through. So, *starting from the
>> >wall* at 75 feet, the bolt extends *backwards* the full 80 foot
>> >length. I just toasted myself.
>
>Which is so absurd that we never played it that way. We used the rule
>from the Real World (tm) that "the angle of incidence is equal to the
>angle of reflection." One could only toast one's self if one hit the
>wall at a perfect ninety degree angle (which did happen from time to
>time, when people forgot to aim properly...).
>
>And yes, that made bank shots possible.
>
>Baird

From the real world?

Pretty sure there was a discussion on this some time back, but in the
real world, lightning would travel back along its own ionized path, not
reflect like a pool ball...

Thus it would go back towards the caster, making the actual rules as
stated more accurate (in said real world).

It all depends on which 'real world' rules you are attempting using
to explain your magical effects (and which you are ignoring).
 >> Stay informed about: Dirty Spellcaster Tricks 

Aaron wrote:
> From the real world?
>
> Pretty sure there was a discussion on this some time back, but in the
> real world, lightning would travel back along its own ionized path, not
> reflect like a pool ball...
>
> Thus it would go back towards the caster, making the actual rules as
> stated more accurate (in said real world).

Actually, in the real world lightning arcs from a region with a high
density of negative charges to a region with a high density of positive
charges (which in the case of cloud-to-ground lightning is Earth's
surface). There's no way it could be convinced to go back to its origin
no matter how conductive the path.

That means that "realistic" DND lightning would arc from the caster's
fingertip to wherever the easiest way to get into the ground was. Since
the spell causes it to go in a straight line I'm assuming the spell
pre-ionizes a path for it to follow through the air, but once it's hit
something that's standing on the ground it probably wouldn't go beyond that.

Of course, DND lightning isn't "realistic"; it's a magical death-beam
that follows its own rules. If those rules say it bounces, I guess it
bounces.
 >> Stay informed about: Dirty Spellcaster Tricks