Never heard that explanation before, that highground-advantage only works for attacks 'from the front' and gets cancelled if the attack from below hits the unit on top from behind (splash damage from a targeted unit standing behind it).
And on top of that, that the attack cancellation under Dark Swarm can be selectively circumvented in the same way, by targeting DSed units in the back with a splash-attack...
Thanks a lot for sharing.
edit: Maybe you want to change the title and include the highground-advantage-cancellation-thing in there. Like "How to cancel DS/highground-advantage"
Yeah, I used to kill single lurkers under ds with a medic and tankshots. Wins you one out of 10k games, if zerg is teching really greedy. Also nice to know for micro tour.
Hah, I tought missed shots just were gone. I think for leapfrogging uphill to your third base in TvP, this might be useful. It makes siege tanks uphill a lot better than I thought they were.
Well, there's nothing new about this. From the comments it seems like half the people in this thread still have not completely understood it yet, though, maybe because of the somewhat crude translation in the subtitles.
What is miss chance? Miss chance only applies to ranged, direct impact attacks (from both air and ground units) and has the following effects:
The point of impact of the attack is moved one tile 30px (according to OpenBW code) towards the attacker.
All direct damage is nullified. Splash damage still applies, but around the actual point of impact.
When does miss chance apply?
There is always a miss chance of 1/256 (.390625%).
Ground units on lower ground have a 120/256 (46.875%) chance to miss ground units on higher ground. Air units are not affected, neither when attacking nor when being attacked (but can still profit from the vision blocking effect that higher ground gives). + Show Spoiler [some technical details] +
There are three terrain levels in Brood War: low, medium and high ground. These are determined by minitile flags (small areas of 8x8 pixels). A unit's terrain level is determined by the flag of the minitile at its exact position, below the centre point of its collision box, coordinates rounded up to full pixels. Miss chance is the same from low to medium, low to high and medium to high ground.
There is a tile flag that causes a miss chance (known as cover effect) for units positioned on certain doodads/doodad tiles. This miss chance is also 120/256 (46.875%) and effects both air and ground attackers, independent of their terrain level. There is no stacking effect with high ground miss chance. + Show Spoiler [some technical details] +
Units do not actually have to be positioned visibly behind the doodad sprite, in fact for most doodads this will have no effect at all, except for visibly obscuring the unit. To gain cover they need to be placed on one of the doodad tiles. A tile is a basic terrain block of 32x32 pixels. Unit position is determined as below the centre point of its collision box, coordinates rounded up to full pixels. Cover providing doodads roughly encompass the following :
tree doodads in Badlands
tree doodads in Jungle
most of the hut doodads in Desert as well as most of the bulkier plant doodads and the big derelict CC and derelict factory doodads.
the more bulky building on snow doodads in Ice.
none of the doodads in any other tileset provide cover.
Dark Swarm grants a 100% miss chance for units under it, effecting both air ans ground attackers. Unlike the other sources of miss chance, Dark Swarm does not apply to buildings.+ Show Spoiler [some technical details] +
Again, what determines whether a unit is considered under Dark Swarm cover is not any kind of overlap of the visible sprites but whether the unit's collision box overlaps the Dark Swarm's one, which is a square of 160x160 pixels.
Different sources of miss chance do not stack up. Only the highest miss chance applying to any particular source of damage will be applied
Useful notes:
melee attacks are not affected
pure splash attacks (no point of impact) are also entirely unaffected. this is why the linear splash attacks of Lurkers and Firebats as well as the suicide splash attacks of Scarabs, Spider Mines and Infested Terrans still fully apply.
For bouncing shots (Mutalisk) miss chance is only evaluated for the first hit. If the original attack misses, the shot will not bounce, but when it hits, the bounces will also hit their targets with 100% chance, disregarding any miss chance.
miss chance has no effects on spells.
burrow negates partial splash. To damage burrowed units they need to be within the 100% splash radius of a radial splash attack, which is why they can still be killed with indirect shots, but need to be hit directly at the point of impact.
It is actually pretty easy to accurately predict where the point of impact of missed shots will be. It is moved by about 1 tile (30 pixels) towards the attacker along a straight connection. Since 32x32 pixels is the collision size of most big units, such as Lurkers, Dragoons, Reavers, Archons or Factory units, if a tight group of such units is targeted, shots missing a unit in the back will fully hit the row of units in front of it.
Missed shots of sieged Tanks will land inside its minimal attack range of 2 tiles (64 pixels), but still not close enough to damage the tank itself.
On November 08 2017 21:36 james1024 wrote: Hey yo like an above poster said, I remember Last suiciding medics to tankshots against zero's swarm'd lurkers. But man, as a zerg, TvZ is HARD
So does this mean an archon's attack is almost on top of itself (even possibly slightly behind itself), since it's short range attack gets pushed back a full tile? Thank you for the immaculate run-down, was only half sure of things after watching the video.
On November 09 2017 04:04 Highgamer wrote: Freakling, did you just pull that overview out of your + Show Spoiler +
brain
or do you have some source you can quote such stuff from in well organized written form?
Freakling's post are generally like that. Very detailed and well formatted. Quite commendable! He really gets going when the subject is anything map related! ^^
On November 09 2017 04:04 Highgamer wrote: Freakling, did you just pull that overview out of your + Show Spoiler +
brain
or do you have some source you can quote such stuff from in well organized written form?
Some of it can be found on liquipedia, albeit spread across multiple articles and requiring some searching and link chasing. The exact probabilities can be found somewhere on the BWAPI pages, which are a great source for most of the more technical aspects of the game. Another (as-good-as-) first-hand source is the OpenBW project on sourceforge, but you'd have to search through several hundred lines of code to find governing functions. Apart from that I have learned not to trust any sources a long time ago, as they are just completely wrong more often than not, and become my own best source. I don't make any claims I have not tested thoroughly in-game.
On November 09 2017 04:04 Highgamer wrote: Freakling, did you just pull that overview out of your + Show Spoiler +
brain
or do you have some source you can quote such stuff from in well organized written form?
Apart from that I have learned not to trust any sources a long time ago, as they are just completely wrong more often than not, and become my own best source. I don't make any claims I have not tested thoroughly in-game.
On slightly off-topic note, do you happen to know what determines where larvas sit at the hatcheries? Am I going crazy or they funnel to the opposite side of the mineral line?
You aren't going crazy. I don't know how exactly it works algorithmically, but it is pretty clear that Larvae spawn on a free side of the Hatchery (side not blocked by buildings or units). The general preference seems to be bottom>left>right>top side.
On November 09 2017 04:43 Chronopolis wrote: So does this mean an archon's attack is almost on top of itself (even possibly slightly behind itself), since it's short range attack gets pushed back a full tile? Thank you for the immaculate run-down, was only half sure of things after watching the video.
For bulky units such as Archons, Dragoons or unsieged Tanks this means indeed that the impact of a missed attack will be right on top of the attacker (the distace from unit centre to unit centre being exactly one tile if they are directly horizontal or vertical to each other). For smaller units, such as Hydras or Marines, which can fit closer than one tile together, you really get the effect where the impact is basically right on the back of the head of the attacker. Looks rather funny.
Adding to what freakling said (I also have the impression larvae spawn at side not blocked by building and that they prefer the bottom if the bottom is available), you can tell larvea to move to the left by selecting a larvea together with another unit (usually an overlord) and pressing 's'. Good zergs always do this when the mineral patches are on the left side, so I'm guessing it's pretty common knowledge, but some newer players might not be aware of it.
While the mineral benefits from doing this is pretty negligible, there are situations outside the early game where it can be very useful. For two such examples, if I play zvt on fighting spirit against someone who opens factory and I'm in the top right spawn location, I like to build my third hatch at my natural making a slight wall, and then the sunken is slightly above and in the middle. Sometimes the terran is able to position a vulture so that they can kill the larvea spawning below the hatchery - which seriously hurts my production - but then if whenever a new larva spawns I immediately tell it to stop so it moves to the left, it ends up being covered by the sunken. Another is in zvp, where moving larvea to the left side can in some instances make your sim city way stronger through blocking an area the zealots would otherwise be able to get through.
Another small but interesting thing about larva is, when you select 2-3 larvae and try to make a unit, the game seems to always use the larva farthest to the right, so if you want to use the larva trick, make sure you are selecting the correct larva or the wrong one will be used.
Well, there's nothing new about this. From the comments it seems like half the people in this thread still have not completely understood it yet, though, maybe because of the somewhat crude translation in the subtitles.
What is miss chance? Miss chance only applies to ranged, direct impact attacks (from both air and ground units) and has the following effects:
The point of impact of the attack is moved one tile 30px (according to OpenBW code) towards the attacker.
All direct damage is nullified. Splash damage still applies, but around the actual point of impact.
When does miss chance apply?
There is always a miss chance of 1/256 (.390625%).
Ground units on lower ground have a 120/256 (46.875%) chance to miss ground units on higher ground. Air units are not affected, neither when attacking nor when being attacked (but can still profit from the vision blocking effect that higher ground gives). + Show Spoiler [some technical details] +
There are three terrain levels in Brood War: low, medium and high ground. These are determined by minitile flags (small areas of 8x8 pixels). A unit's terrain level is determined by the flag of the minitile at its exact position, below the centre point of its collision box, coordinates rounded up to full pixels. Miss chance is the same from low to medium, low to high and medium to high ground.
There is a tile flag that causes a miss chance (known as cover effect) for units positioned on certain doodads/doodad tiles. This miss chance is also 120/256 (46.875%) and effects both air and ground attackers, independent of their terrain level. There is no stacking effect with high ground miss chance. + Show Spoiler [some technical details] +
Units do not actually have to be positioned visibly behind the doodad sprite, in fact for most doodads this will have no effect at all, except for visibly obscuring the unit. To gain cover they need to be placed on one of the doodad tiles. A tile is a basic terrain block of 32x32 pixels. Unit position is determined as below the centre point of its collision box, coordinates rounded up to full pixels. Cover providing doodads roughly encompass the following :
tree doodads in Badlands
tree doodads in Jungle
most of the hut doodads in Desert as well as most of the bulkier plant doodads and the big derelict CC and derelict factory doodads.
the more bulky building on snow doodads in Ice.
none of the doodads in any other tileset provide cover.
Dark Swarm grants a 100% miss chance for units under it, effecting both air ans ground attackers. Unlike the other sources of miss chance, Dark Swarm does not apply to buildings.+ Show Spoiler [some technical details] +
Again, what determines whether a unit is considered under Dark Swarm cover is not any kind of overlap of the visible sprites but whether the unit's collision box overlaps the Dark Swarm's one, which is a square of 160x160 pixels.
Different sources of miss chance do not stack up. Only the highest miss chance applying to any particular source of damage will be applied
Useful notes:
melee attacks are not affected
pure splash attacks (no point of impact) are also entirely unaffected. this is why the linear splash attacks of Lurkers and Firebats as well as the suicide splash attacks of Scarabs, Spider Mines and Infested Terrans still fully apply.
For bouncing shots (Mutalisk) miss chance is only evaluated for the first hit. If the original attack misses, the shot will not bounce, but when it hits, the bounces will also hit their targets with 100% chance, disregarding any miss chance.
miss chance has no effects on spells.
burrow negates partial splash. To damage burrowed units they need to be within the 100% splash radius of a radial splash attack, which is why they can still be killed with indirect shots, but need to be hit directly at the point of impact.
It is actually pretty easy to accurately predict where the point of impact of missed shots will be. It is moved by about 1 tile (30 pixels) towards the attacker along a straight connection. Since 32x32 pixels is the collision size of most big units, such as Lurkers, Dragoons, Reavers, Archons or Factory units, if a tight group of such units is targeted, shots missing a unit in the back will fully hit the row of units in front of it.
Missed shots of sieged Tanks will land inside its minimal attack range of 2 tiles (64 pixels), but still not close enough to damage the tank itself.
I actually didn't know this. I just thought the miss chance just made the attack do zero damage.
EPT
