Non-glitch tricks

[Clam]

A companion to the glitch thread.

The glitch thread lists a lot of tricks that are useful for challenge solutions, but there are plenty more tricks that don't enter the realms of 'glitchiness', but instead emerge from intended game mechanics. Deciding what is a worthwhile trick is even more hazy than defining glitches (geoo on IRC: "Have a Lemming walk against a wall to turn him around"), but as a first stab at a filtering criterion, I'll try to include anything that isn't required to achieve glitch-free solutions to the original levels. And since some of these are borderline glitchy, there may be some overlap between this and the glitch thread.

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DOS

Climbers

Floaters

• You can assign the floater skill to a lemming at the bottom of a long fall, and it will survive. This saves time, as floaters descend slower than fallers.

Bombers

• Falling bombers detonate immediately, without going through the 'ohno' animation, saving some time.

Blockers

• When assigned to a lemming (usually digger) that has no terrain under its centre pixel, it will stop, revert to walker for one frame, and then fall. The lemming advances one step in the walker frame, so if there is a terrain pixel at feet level one pixel in front of it, it will walk on.
• Can turn around lemmings in most states, not just walkers (and builders, à la Mayhem 5)
• Pass-through blocker: Assign at the bottom of a fall / top of a climb, and incoming lemmings will pass through it. Depending on the positioning of terrain relative to the grids, this effect can be achived with a 45° upwards slope.
• Bashable pass-through blocker: As above, but with an increase in height between the landing spot and the blocker, so it can be removed with a basher.
• Even without a pass-through, you can still remove a blocker on slightly higher ground with a single basher, depending on the blocker's position relative to the grids.
• The blocker's field extends up and down slighty (again, the exact positioning depends on the grids). This means you can sometimes turn lemmings on a different platform to the blocker.
• If the blocker is placed at the correct horizontal position relative to the grid (1 of each 4 positions works), you can free it by assigning a digger to a turning lemming.

Builders

• Builders only check for terrain in two pixels after each brick they place, one above the head ('ceiling check') and one at the feet ('floor check'). This allows them to squeeze through terrain formations in unintuitive ways. The ceiling check is further forward than the floor check, meaning builders will build further into low walls (< 11 pixels) than high ones. Additionally, the ceiling check is skipped on the last brick.
• Due to the asymmetry of builders, left-facing builders place a pixel of terrain behind them.
• Walling: Lemmings will turn around whenever they encounter a 7-pixel or higher obstacle in their path. Depending on the terrain shape and availability of other skills, there are a vast number of setups that can be used to achieve this.
• By repeatedly assigning builders to a lemming close to a ceiling, you can force it into the ceiling.
• It is possible to build in front of a thin pillar, and have part of the brick extent to the other side of the pillar.
• Speedbuilding: There are various ways of using multiple builders to move faster (horizontally or vertically) than a single builder can. The key points are (1) the builder places a brick halfway through its animation, after which you can stop it or have the next lemming overtake it, and (2) a new builder can add 5 pixels (4 if facing left) to the end of the bridge (bridge-stretching), whereas the regular builder only adds 2 at a time. Types of speedbuilding include: releasing lemmings at RR88 and having each build as late as possible; alternating builder and basher (bash as soon as the lemming steps onto the new brick); alternating builder and basher with two lemmings (this is only slightly slower than the RR88 setup).
• 'Stepover' turnaround: Release two lemmings in quick succession (anywhere from RR68 to 99 works), build on flat ground with the first lemming, and build with the second lemming as soon as it steps off the brick placed by the first. The next brick of the first lemming will trigger the 'floor check' for terrain on the second builder, causing it to turn around. It is possible to create an equivalent setup in other situations, eg. on a bridge in progress (see Wild 17 builders+bashers).
• Shrugger turnaround (aka. the alfonz1986 trick): Somewhat similar to the above; use the time taken by a builder to 'shrug' to build a brick over it, then start the shrugger building just before it finishes shrugging. The second builder can build two bricks before the shrugger moves again, which triggers the floor check and causes the shrugger to turn around.
• 7-builder stack: Let out 7 lemmings at RR88, and have each build as soon as it steps onto the brick laid by the previous one. This creates an impassable wall for the remaining lemmings, and all but 2 builders turn around due to floor checks. Other variants of this trick exist, see http://www.lemmingsforums.com/index.php?topic=558.msg11658#msg11658" class="bbc_link" target="_blank">here for more.
  
• Lemmings walk over bridges one way and under the other way, eg. if you build to the right, then any lemmings walking beneath the bridge will be facing left. This allows you to pick out a lemming facing the right way. Lemmings falling onto the bridge are a possible exception; this leads to a neat method of isolating the last lemming that falls.
• The terrain added to the level by builders can be used to keep a basher/miner/digger going, by providing them with ground to stand on and/or terrain to satisfy the check to make them continue digging.
• Builders don't check for terrain underneath them, so they can continue even if the ground under them is removed.

Bashers

• Bashers can be stopped mid-stroke by assigning another skill, leaving a ramp that other lemmings can walk up. The usual way to do this is a builder, but blocker, digger, and even bomber (timed so the countdown ends mid-stroke) can work.
• The basher's exact terrain-detection mechanics can be exploited in various ways, see http://www.lemmingsforums.com/index.php?topic=558.msg11658#msg11658" class="bbc_link" target="_blank">here (bottom section of the post) for details.
  
• Bashers remove terrain in the column of pixels they are standing in, meaning you can take a 'backstroke' into the wall by assigning the skill to a lemming as it turns around.
• Three-basher ramp: Release two lemmings at RR86, and another at RR99. Bash into a wall with the first lemming. The second lemming will step up as the basher makes its second stroke, and for one frame will be a walker in mid-air; assign it a basher on this frame, then bash in front of this, as late as possible, with the third lemming. The second and third bashers will stop and fall to the ground, and the first basher will stop since the third basher removes the terrain it checks for in front of it. The net result is a 5-pixel gain in height, at the cost of 3 bashers. Other setups are possible, what matters is that the lemmings are in the right place at the right time. This is the key to many of the basher-only challenges, eg. http://www.lemmingsforums.com/index.php?topic=114.msg1993#msg1993" class="bbc_link" target="_blank">Fun 14 (in fact, this one uses a different setup that gains even more height per basher).
  
• Bashers slide down slopes they encounter in the terrain below their feet. This can be exploited by mining or digging at the basher's position to make it bash lower.
• Because of the positions of the basher's terrain and steel checks, it is possible to bash before a steel block in such a way that the terrain check succeeds on the first stroke, but the assignment isn't prevented by the steel check. This means the lemming takes one swing towards the steel and turns around. This can be useful if you want to turn a climber, or if the steel block isn't attached (but is in the basher's reach) from the platform the lemming is on.

Miners

• As with bashers, miners can be stopped mid-stroke to create a ramp. This works in conjunction with the miner-positioning glitch, as the ramp coincides with the time when the lemming is wrongly positioned one pixel too low.
• Miners remove terrain in the column of pixels they are standing in and the column behind, meaning you can take a 'backstroke' into the wall by assigning the skill to a lemming as it turns around.
• Speed mining: Using multiple lemmings, or a single lemming alternating with other skills, it is possible to progress across and/or down faster than a regular miner. This works especially well in conjunction with diggers.
• Undermining: By mining into the position of an existing miner that has just taken a stroke, you can remove the ground beneath it, and this stop it. This can be done in either direction; undermining backwards is especially useful as it allows zig-zag tunnels to be made.
• A lemming walking on steel can be turned around by building one brick, and then mining.
• Miners remove terrain above and in front of them. By mining off the end of a bridge in progress, you can keep a builder going. For an example, see http://www.lemmingsforums.com/index.php?topic=170.msg4870#msg4870" class="bbc_link" target="_blank">Fun 15 with 2 builders.
  
• Basher-miner stop: It is possible to make a basher and miner come together in such a way that they both stop. This can be done with the basher and miner going in opposite directions, or with both going the same way. For an example of the latter, see http://www.lemmingsforums.com/index.php?topic=85.msg1293#msg1293" class="bbc_link" target="_blank">Tricky 19 in 1 minute.
  
  DiggersWTF is up with this formatting
  
• Similar to undermining, diggers can be stopped by digging on their exact position. (In other ports, assigning a little either side works too, DOS is unusual in this regard.) As with undermining, this can be done in the same direction as the first digger, or the opposite direction.
• Diggers continue for a few frames once last terrain is gone. In this time, it it possible to assign another skill (eg. builder).
• It is possible to turn a right-facing builder by digging immediately after it places a brick, descending 3 pixels, and building again. The digger leaves a single pixel of brick that triggers the floor check for the next builder.
• By alternately building a few steps and digging down a few pixels, you can make a lemming move sideways through air.
• Speed-digging: As with speed-mining, use multiple lemmings or alternate diggers with other skills to dig faster. Works especially well in conjunction with miners. For a demonstration see this animated gif: http://cfile6.uf.tistory.com/media/012E0C3E51700B5B2FFBF6" class="bbc_link" target="_blank">http://cfile6.uf.tistory.com/media/012E0C3E51700B5B2FFBF6
  
• Diggers can be used in conjunction with bashers or miners to create steep ramps in solid terrain. Basher/digger in particular can create a ramp of any slope (the maximum that lemmings will walk up is 6:1).

Other

• In some cases, it can be useful to isolate last lemming that enters the level, and use this lemming to build the path to the exit.
• When there are two or more lemmings under the cursor, the last lemming (in order of their entrance to the level) has priority for selection. This means you can choose a lemming facing the right way by keeping track of the last lemming out. Later lemmings are drawn over the earlier ones as well, which can help you find the last lemming sometimes.
• Lemmings 'jump' (ascend) when they encounter a rise of 3-6 pixels, and fall when they encounter a descent of 4 pixels or more. This slows the forward movement of the lemmings. Such rises and falls can be created and destroyed, and can affect timing in various ways. For example, leveling out the terrain can get the lemmings to the exit faster in a speedrun-type solution.
• Merging: Making two or more lemmings occupy the exact same position on the level is useful for many reasons.slidingThe easiest way to force this is with a pair of blockers, but a vast number of methods exist.

[Gronkling]

You can use builders to extend bashers length like in this video: http://www.youtube.com/watch?v=CgfnU2RGjek#" class="bbc_link" target="_blank">Lemmings - Custom level

[ccexplore]

Yep, that's basically a combination of these two points Clam mentioned:

The terrain added to the level by builders can be used to keep a basher/miner/digger going, by providing them with ground to stand on and/or terrain to satisfy the check to make them continue digging.

Bashers slide down slopes they encounter in the terrain below their feet. This can be exploited by mining or digging at the basher's position to make it bash lower.

===============

I'll also add the following:

7-builder stack: Let out 7 lemmings at RR88, and have each build as soon as it steps onto the brick laid by the previous one. This creates an impassable wall for the remaining lemmings, and all but 2 builders turn around due to floor checks.

I'll like to add that about 2-3 months ago I've found an improvement to this basic technique, as you might've seen from some of my recently posted replays.  Basically, to get a stack of height N pixels, you can use just N-2 lemmings at RR88 and use N-1 builders.  You do an N-2 stack just like the above, but then after the last turnaround builder has turned around and has just stepped up onto the highest point of the stack, assign him builder again.  He will complete the last 2 pixels of height you need for your stack, and will actually trigger the floor check on one more lemming.  So you end up turning around all but 1 builder, and use one less builder than the basic stack technique above.  Of course, because the last 2 build bricks are laid by the same builder, it will take slightly longer for the stack to reach the desired height this way.

Note: this works both facing left as well as right, but I think you have to take some care with the builder placement for left due to the asymmetry of brick placement for left builders

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Lemmings walk over bridges one way and under the other way, eg. if you build to the right, then any lemmings walking beneath the bridge will be facing left. This allows you to pick out a lemming facing the right way.

A collorary to this is that if your bridge goes up to the left, does not connect with a wall, and is right underneath an entrance trapdoor, you get a nice setup where you can have a lemming coming out of the trapdoor start building right, and only subsequent lemmings from the trapdoor will follow that bridge, while the rest of the crowd will not, until you release them with another builder.

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Another useful builder technique is to take advantage of their crude ceiling check.  Basically only a single pixel of ceiling is checked each time a lemming steps up onto the brick he lays, plus the ceiling check is skipped entirely on the final brick.  The ASCII diagrams below depict exactly the check:

(X = ceiling check location, * = where lemming is standing, + = the build brick being laid down, before builder steps up onto brick and checks for ceiling; . = nothing [just annotation to help line you up visually])

Code: [Select]

10     X
 9     .
 8     .
 7     .
 6     .
 5     .
 4     .
 3     .
 2     .
 1 *+++++
.
10 X
 9 .
 8 .
 7 .
 6 .
 5 .
 4 .
 3 .
 2 .
 1 ++++*+   
Some useful techniques deriving from this mechanic:

• Notice that the builder moves forward 2 pixels each time, so with certain ceilings (eg. 1-pixel thin icicle tips), if you plan carefully where you start building, you can "skip" over low points in the ceiling that are only 1-pixel in width.
• It's actually typically the ceiling check that stops the builder when he builds into a wall.  However, if the wall you are building into is not that high, then instead of the ceiling check the builder will only be stopped by the floor check, which means he can get a bit closer to the wall before his building is interrupted.  A simple example is to compare how many build bricks you can lay when assigning builder to a digger, with a digger's pit of height 10 vs height 11 on flat ground.
• Also notice that this means your builder will completely ignore terrain between roughly from his head to his legs, as such terrain will trigger neither the ceiling nor the floor checks.

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The asymmetry with the placement of the build brick by the left-facing builder means you get a pixel of brick immediately behind where the builder is standing.

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basher/miner "backstroke":  the basher removes 9 pixels from the vertical column of pixels at his standing position, while the miner removes 12 pixels from both that column plus the column immediately behind.

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how to plan your basher:  by understanding exactly how the basher checks for more terrain to continue bashing, you can better plan where to start bashing to achieve particular outcomes (eg. have the basher automatically stop, or to continue through patches of insufficient terrain):

1) All the pixels being checked are vertically at 6 pixels above the floor level of where the lemming is standing when the bash stroke is made (eg. from the pixel of floor terrain lemming is standing on top of, move up 6 pixels and that's the height we're looking at).

2) At that height, the game checks the pixels from 8 to 11 pixels horizontally away from where the lemming is standing (obviously in the direction he's facing), and will continue bashing if at least one of these 4 pixels are terrain.  The basher's full stroke reaches 7 pixels horizontally in front of the lemming, so very roughly speaking, this means the basher continues bashing if there is more terrain immediately following the current end of the bash tunnel.  It doesn't even matter if the bash stroke just made didn't take out a single pixel of terrain, as long as there's more just beyond the reach of the stroke (at the right height of course).

3) This check is skipped on every other stroke, specifically the even-numbered strokes (counting from 1).  In other words, without falling or steel or other such interruptions, a basher will always stop after making an odd number of strokes, not even.

4) The basher moves forward 5 pixels after each stroke.

Armed with this information, the attached sketching can be used to help plan out your bashers in situations where you need to do so.  The red dot represents the floor pixel the lemming is standing on when he starts bashing, and the yellow "dashes" are where terrain is being checked in order to continue bashing.  The green dots represents the floor pixels the lemming will be standing on for each subsequent bash stroke after the 1st (skipping over the even strokes), in case the basher drops lower over the course of his bashing.

[edit: include attachment http://www.lemmingsforums.com/Smileys/lemmings/XD.gif" alt=":XD:" title="XD" class="smiley" />]

[Clam]

Thanks for the detailed post ccx, I've added those points to the OP. The builder-stacking method is particularly noteworthy; I wonder if there are any more challenge solutions to be found with the extra builders freed up here.

[mobius]

this is nothing new, but some one showed me this gif and I thought it would be noteworthy to ad to this post. It really demonstrates 'speed mining/digging'  http://www.lemmingsforums.com/Smileys/lemmings/shocked.gif" alt=":o" title="Shocked" class="smiley" />

http://cfile6.uf.tistory.com/media/012E0C3E51700B5B2FFBF6" class="bbc_link" target="_blank">http://cfile6.uf.tistory.com/media/012E0C3E51700B5B2FFBF6

[Clam]

Nice gif, I've added the link to the top post. So I can attribute credit, where did you get this from?

[mobius]

ssam1221 on youtube showed me. I don't know if he made it or just found it.

[GuyPerfect]

ssam1221 on youtube showed me.

You should message him and ask. (-:

[ssam1221]

ssam1221 on youtube showed me. I don't know if he made it or just found it.

I found this trick and created this GIF(in fact, SWF) file.

This trick needs 1-frame control, so if you use this trick, you may be playing with Lemmix because Lemmix support 1-frame control using pause.

Of course you can 1-frame control without pause, you can use this trick any version lemmings. But it is impossible.

I don't know other lemmings program support 1-frame control.