Advanced Blocker tricks

[Strato Incendus]

As a beginner, you tend to do everything with Blockers: The crowd always needs to be contained between two Blockers before you can even start planning the solution.
As an intermediate player, you get used to all the methods of crowd containment without any Blockers: Basher / Miner / Digger / Bomber pits, sealing off shafts with Builders or Platformers, Stackers and anticipating how many Lemmings will slip by, Stoner cells which you can only free the crowd from with Stackers, etc.
As a professional, also when it comes to the levels you design yourself, you might discard containing the crowd alltogether and instead move more and more towards mere flow control and timing-based solutions.

And then, finally, suddenly, the Blockers start popping up on the skill panel again. But they're almost never supposed to be used in the way regular players are used to.

I find myself having the most trouble with solutions where levels provide Blockers, but at first glance, it always seems like not a single one of them can be used, because there don't seem to be enough opportunities to easily free them again. The Builder may be the most powerful classic Lemmings skill, but the Blocker is definitely the most complicated one.

So I'd like to collect all the advanced tricks here involving Blockers. I'm trying to get back into Nepster Lems at the moment, and often whenever I compare my solutions or attempts at solutions to IchoTolot's walkthrough on YouTube, there are tricks involved which I wouldn't even have considered in my wildest dreams. It brings back some memories of SubLems and Lemmings Migration, when there are certain levels which you have no chance of solving, simply because you weren't aware that a certain approach is even possible from a pure game-mechanics standpoint.


I'll therefore try to somewhat categorise the Blocker tricks I am aware of, but I'm certain this list isn't complete, so please add to it!

The Fake Blocker

This type of trick could be summarised, in the quickest way I can put it: The destructive skill freeing the Blocker is initiated before the Blocker itself is even assigned!
This works predominantly with Bashers and Diggers.

• The Basher-Blocker-Turnaround. At a certain moment during a Basher's motion, it creates a slope which other Lemmings can step onto. This slope is most commonly used as a surrogate-staircase, by stopping the Basher right there with a Walker or Builder. In this case, however, it is not the Basher to which the skill is assigned, but the Lemming stepping onto the slope the Basher is currently creating. If timed just right, the Walker will not become a Blocker, not even for a single frame - he will turn into a Faller right away, as the Basher removes the terrain under his feet, but the Basher will still turn around, due to being affected by the Blocker. Since the timing is so difficult with this trick, it's usually easiest to pull of if several Lemmings, or the entire crowd, walk into the Basher tunnel successively, until one of them reaches the Basher slope at just the right moment. Depending on how little terrain the Basher has removed in the meantime, he may even continue in the opposite direction! Usually however, the Basher-Blocker-Turnaround is equivalent to a Basher-Blocker-Cancel, because the Basher is now facing his own tunnel and has no more terrain left to remove.
• The Digger-Blocker-Turnaround. This trick recently sparked some emotional discussion when one user discovered it for himself for the first time: The direction in which a Digger is facing while digging isn't clear. Thus, it isn't easy to notice when this direction is reversed by assigning a Blocker to a different Lemming inside the same Digger shaft. Due to the Digger spending some time in the trigger area of the Blocker, if that trigger area points into the opposite direction, he will turn around, but continue digging. (If the Digger is inside the trigger area forcing Lemmings into the same direction he's already facing, the Blocker won't have any effect on the Digger.) The fact that he has changed the direction in which he is facing can only be observed due to the skill shadow of other skills now pointing into the opposite direction when hovering the mouse over the Digger. Depending on when you assign the Blocker, the Lemming may actually spend a couple of frames as a Blocker before the Digger removes the ground beneath him, turning him into a Faller and then a Walker again. But sometimes, it might just be a single frame, and/or barely visible due to other Lemmings crowding the Digger shaft.
• The Digger-Blocker-Cancel. A Digger who is only digging at the edge of terrain, without actually having any terrain under his feet, can be cancelled by assigning a Blocker to him, since a Blocker's position is always right in the middle under his feet, where the Digger doesn't require any terrain. Just like in the aforementioned case, the Lemming will not become a Blocker for even just a single frame, but turn into a Faller right away. There is no visible difference to assigning a Walker to the Digger at this point.

Passing through Blockers

Blockers have trigger areas on their hands that act just like one-way fields - they turn around Lemmings approaching from the opposing side, leaving Lemmings approaching from the same side unaffected. This is totally obvious with one-way fields; with Blockers, however, due to them having one-way fields pointing in opposing directions on their hands, it is rare to have a Lemming approach from a side that allows passage. But this merely means the direction the Lemming is coming from can neither be left nor right. It is possible however to pass through Blockers from above and, perhaps less obviously, from below!
All these tricks also allow to free Blockers with just a Digger, because the Lemming freeing the Blocker is standing at the exact same spot as the Blocker himself.

• The Blocker right beneath the hatch. This is probably a trick most beginners are already familiar with, because it is easy to discover by accident. It is important as a set-up to understand the other tricks explained in this section, though, so let's repeat it shortly: You can make a Lemming a Blocker on the exact frame that he transitions from being a Faller to being a Walker. This can be done under the hatch, or after any other drop. The centre of his body is now at the exact same point (horizontally) as he was while being a Faller. All following Lemmings will consequently land inside the Blocker, and no matter which direction they are facing, they will continue to walk into that direction, because both one-way fields on the Blocker's hands point into the same direction.
• The Blocker on the slope. If a Blocker stands on a slope which is steep enough for the trigger area on the hand pointing down the slope to not touch the ground, Lemmings will be able to walk up this slope, but not down again if coming from the other side. Keep in mind that the trigger area needs to contain at least one pixel of terrain in order to affect walking Lemmings, just like trap triggers. Therefore, if the Blocker's trigger area is just adjacent to the terrain of the slope, but none of the terrain of the slope is actually inside the trigger area, this still allows Lemmings to pass from below!
• The Blocker on the Basher slope. Now we get into the really obscure territory of combining skill tricks! If you create a Basher slope that Lemmings can walk up, as explained in the spoiler above, and we've already established that Lemmings can pass through Blockers on sufficiently steep slopes, then it's easy to put two and two together: Those Lemmings will happily walk right throw the Blocker. Since the Basher slope is often used as a way to step out of a Basher tunnel, even if that tunnel includes a thin ceiling, you can even have Lemmings walk through a Blocker and then through a ceiling - both of which you would intuitively consider impossible.
• Climbing through Blockers. Just like you can have Lemmings fall through Blockers, which is probably the most common application of "Passing through Blockers", Climbers can also "hoist" through Blockers that are standing right on the edge of a block they're climbing onto.

Turning around on Oh-Noers

These could also be considered Oh-Noer tricks, of course, but they don't work with regular (ex-Walker) Oh-Noers - only with such that were Blockers prior to Bomber or Stoner assignment.

• Falling into the Blocker's Bomber pit. It is possible to have a Lemming turn around on a Blocker who is oh-noing, and then for that turned-around Lemming to still fall into the Bomber pit which is created once the Blocker explodes. From there, he could, for example, start bashing.
• Using Oh-Noers for Lemming segregation. Sometimes several Lemmings are clumped together after having spent some time contained by one or more Blockers. When you bomb the Blocker to free the crowd, but only want a certain number of Lemmings to be close together as the first ones leaving their "confinment", you can use framestepping to assign the Bomber at just the right moment, so that most of the Lemmings clumped together will still turn around on the Oh-Noer, and e.g. only the last one will reach the Blocker right after his explosion. Now you have a single Lemming walking slightly ahead of the released crowd.

Touching the trigger area

The only reason that trigger areas usually need to touch terrain (see above) is because regular Lemmings are usually Walkers, and Walkers have their position marker at their feet, i.e. on terrain. They're only affected if that one pixel moves into a trigger area. For Lemmings not touching the ground, however, trigger areas do not necessarily have to encapsulate terrain!

• Across the gap. A Blocker can stand on one side of a tiny vertical gap, and a Lemming can be approaching from the other side, and that Lemming will still turn around, if the gap is narrow enough for the trigger area to span across it.
• High Five! This one is a favourite of mine: Blockers even affect Fallers passing through their trigger area! So even if there might not be a Blocker on a lower ledge preventing Lemmings from falling into an abyss, that's no problem if you can turn around the Fallers halfway down!

Any further Blocker-related tricks I should be aware of?

[Flopsy]

I'm personally not a fan of documenting tricks on the forums as I feel it is better for someone to play levels and figure things out for themselves rather than have a "cheat sheet" like this topic to refer to.

There are a lot of Blocker tricks not on this list in my upcoming pack anyway so this list is by no means exhaustive!

[namida]

The Basher-Blocker-Turnaround. At a certain moment during a Basher's motion, it creates a slope which other Lemmings can step onto. This slope is most commonly used as a surrogate-staircase, by stopping the Basher right there with a Walker or Builder. In this case, however, it is not the Basher to which the skill is assigned, but the Lemming stepping onto the slope the Basher is currently creating. If timed just right, the Walker will not become a Blocker, not even for a single frame - he will turn into a Faller right away, as the Basher removes the terrain under his feet, but the Basher will still turn around, due to being affected by the Blocker. Since the timing is so difficult with this trick, it's usually easiest to pull of if several Lemmings, or the entire crowd, walk into the Basher tunnel successively, until one of them reaches the Basher slope at just the right moment. Depending on how little terrain the Basher has removed in the meantime, he may even continue in the opposite direction! Usually however, the Basher-Blocker-Turnaround is equivalent to a Basher-Blocker-Cancel, because the Basher is now facing his own tunnel and has no more terrain left to remove.

Are you sure this one is actually possible?

[ccexplore]

Perhaps the detailed description is slightly off in places, but I wonder if Strato's maybe talking about this trick I used on a NeoLemmix contest level?

[Dullstar]

I'm personally not a fan of documenting tricks on the forums as I feel it is better for someone to play levels and figure things out for themselves rather than have a "cheat sheet" like this topic to refer to.

I'd like to offer the opposite perspective for a moment. If you don't know the tricks, it's often hard to discover them unless you have access to levels that are designed to coax the player into trying it, which is very, very difficult to reliably do, since unless you can find a way to make the most obvious solution cause the trick to just kind of happen on its own, a player might not think to try something. This can make a number of packs relying on these packs completely inaccessible, and I've definitely given up on a few levels, watched a replay of the solution, and realized the solution relied on something I didn't realize was possible, or in a few places, something I'd maybe seen in passing once but then never managed to find a practical use for until I kinda forgot about the mechanic.

Without these cheat sheets, unless you're really good at finding these more obscure interactions, probably the most accessible way to find these tricks is to make a bunch of levels and watch the backroute replays come pouring in.

[IchoTolot]

The Basher-Blocker-Turnaround. At a certain moment during a Basher's motion, it creates a slope which other Lemmings can step onto. This slope is most commonly used as a surrogate-staircase, by stopping the Basher right there with a Walker or Builder. In this case, however, it is not the Basher to which the skill is assigned, but the Lemming stepping onto the slope the Basher is currently creating. If timed just right, the Walker will not become a Blocker, not even for a single frame - he will turn into a Faller right away, as the Basher removes the terrain under his feet, but the Basher will still turn around, due to being affected by the Blocker. Since the timing is so difficult with this trick, it's usually easiest to pull of if several Lemmings, or the entire crowd, walk into the Basher tunnel successively, until one of them reaches the Basher slope at just the right moment. Depending on how little terrain the Basher has removed in the meantime, he may even continue in the opposite direction! Usually however, the Basher-Blocker-Turnaround is equivalent to a Basher-Blocker-Cancel, because the Basher is now facing his own tunnel and has no more terrain left to remove.

Are you sure this one is actually possible?

Yes, if you remember I even created an alternative solution to a LP VI level (Caveflower) this way. It's not really a favorite in terms of tricks for me as it's always pixel-precise and usually timing heavy, that's why I personally don't use it in my levels.

For the documentation discussion: I think the new Introduction pack will soon be very helpful in teaching the basic/common bag of tricks you encounter. There the player will have text and live level examples.

[ccexplore]

For any trick, by definition there is always someone who's the first to discover the trick, and by definition (s)he would've discovered it without the aid of a cheat sheet nor an example level.  But also by definition, such discovery does not come about specifically from solving a level requiring it (since the trick has not yet been discovered at that time).  It would instead come from some combination of thinking deeply about interactions of certain skills (and then trying it out, maybe learning something new if things didn't work out quite the way you envisioned), from accidentally achieving or observing something as you play around ad-hoc in a level, etc.  One can argue that trying to discover a trick that you haven't known before by solving a level that turns out to require it (but you don't know it does beforehand), could actually be somewhat harder than discovering it on your own in other contexts, because you are likely to be distracted by trying to solve the level other ways first.

I think at least some people here are decent at discovering new tricks on their own without explicitly being taught via cheat sheet or a demo level.  That said, not everyone will be adept at that, and I don't have a problem making things more accessible via cheat sheets and demonstration levels.  After all, no one is forcing anyone to use those resources, so if you'd rather work things out on your own, then simply don't peek at the cheat sheets.  This is no different than the Internet having tons of walkthroughs for many, many games out there.  Even back in the days of Lemmings 1 when the Internet is still at its relative infancy, books had been published containing solutions to all levels (and, hence, all the tricks required to solve them).  Plenty of people were able to complete the game without such a book, but I'm sure there were also countless others who were helped by the book to get through some levels that were particularly challenging for them.  And with custom levels sometimes tending to be much more difficult than the original game's levels, often utilizing a much wider repository of new "tricks" never featured in the original, it makes sense that there'd be a greater demand for cheat sheet and other such things.

[Strato Incendus]

For the documentation discussion: I think the new Introduction pack will soon be very helpful in teaching the basic/common bag of tricks you encounter. There the player will have text and live level examples.

That is precisely what the Noisemaker rank of Lemmings World Tour was also designed to do, as you might find out soon . But since then, I've already discovered several new tricks which I weren't able to feature on that rank, despite it having 40 levels, so that "list" of tricks showcased by the Noisemaker rank isn't exhaustive either.

I'm personally not a fan of documenting tricks on the forums as I feel it is better for someone to play levels and figure things out for themselves rather than have a "cheat sheet" like this topic to refer to.

That's why I put them in spoilers!

I'm with Dullstar on this one; levels that rely solely on an obscure trick to be solvable are hit or miss, i.e. either the player has the knowledge about this trick being possible, then it's easy, or they don't know this can be done at all, and therefore don't even consider it. That's a recipe for dividing the audience into professionals, who already know all the tricks, and noobs who don't have a chance, due to not being able to even consider these approaches - without any "intermediates" in between.

I've also criticised original Lemmings levels like "I have a cunning plan" for not enforcing their trick reliably enough.

I have a cunning plan

This level can teach you either the three-builder wall, or the fact that blockers can be freed by miners, even though the latter is not supposed to be taught until "No added colors or Lemmings".

The main thing with the tricks involved in custom NeoLemmix levels is that, due to framestepping, you can use tricks which require absolute pixel precision and still make the entire solution of the level depend on them. While framestepping facilitates these solutions, or even just enables them in the first place, spotting that something is possible is a lot harder when the necessary components occur during one or two frames - like, for example, everything involving stopping Bashers or Miners mid-stroke to create slopes.

In comparison to that, things like a wall of three builders, or just freeing a blocker with a miner in general, take a really long time and are therefore much easier to discover, just by putting two and two together and trying them out.

[Proxima]

I'm with Dullstar on this one; levels that rely solely on an obscure trick to be solvable are hit or miss, i.e. either the player has the knowledge about this trick being possible, then it's easy, or they don't know this can be done at all, and therefore don't even consider it. That's a recipe for dividing the audience into professionals, who already know all the tricks, and noobs who don't have a chance, due to not being able to even consider these approaches - without any "intermediates" in between.

As someone who is firmly in the "intermediate" category, I rather resent the implication that I don't exist!

All tricks are possible to discover, in theory, because Lemmings has a finite space of possibilities you can attempt on a given level -- albeit the possibility space is, in a sense, much larger than in a game like DROD or Repton, because you can assign skills on any pixel of a lemming's journey. (But when thinking about possible solutions, we don't consider every individual pixel, but rather, make broader decisions on where it does and doesn't make sense to place certain skills, even if some of the windows we consider are rather precise.)

I'm going to link here a post from the DROD forums that describes very succinctly the "cycle" of solving a puzzle, which applies equally well to both games. (The following post, much more detailed, is worth reading as well.)

In a good puzzle, at some point in solving that puzzle you are going to get stuck, and have to look carefully over the space of possibilities, and in particular the assumptions you have probably fallen into, to see what can be adjusted. I'll give an example from a Lemmings/Lix level -- obviously this will necessarily involve spoilers. (It does, however, involve a blocker trick that hasn't been mentioned yet, so it's also relevant to this topic!)

The Top Shelf / Bipolar Maniac

The trick: you need to block on a thin platform to hold the crowd. You can't release them by exploding the blocker, because the platform is thin. But you can release them by exploding a faller just above the blocker, and since this also releases the blocker, it saves the same number of lemmings.

This puzzle is hard because you quickly see the thin platform and make the assumption that you can't explode there. Once you've made that assumption, you stop "seeing" that as part of the possibility space -- until you make the decision to go back and carefully examine your assumptions.

There are some levels, such as Lemmings' Ark, where thinking about a seemingly impossible situation doesn't really lead to a specific "trick", but something more along the lines of "okay, I need to put this skill here and this one here..." But I clearly remember, both from playing the original game and from playing custom levels, that cases where this process of getting stuck and then having to come up with a new insight did lead to the discovery of a new trick (as on Compression Method 1, No added colours or lemmings, Attack of the Subconscious, Don't catch me if you can) were the most satisfying and enjoyable moments of the game. That's why I strongly object to the idea of taking those moments of discovery away from future new players.

This level [I have a cunning plan] can teach you either the three-builder wall, or the fact that blockers can be freed by miners, even though the latter is not supposed to be taught until "No added colors or Lemmings".

As a side note: This level can be done without either trick The solution I originally used was simply to use some builders as delays so that one lemming could be far enough ahead to bash through the pillar.

[Strato Incendus]

As someone who is firmly in the "intermediate" category, I rather resent the implication that I don't exist!

As someone who sees himself in the same category, I can assure that isn't what I said . Rather, all-or-nothing levels like these can make intermediate players like us feel like total noobs, because we might get stuck even on an early rank, when in fact we're intermediate, but simply unaware that certain skill combinations are even possible.

as on Compression Method 1, No added colours or lemmings

I'm only quoting these two, because I'm not familiar with the latter two, but as I've explained above, the mechanics at work here are much slower and don't require pixel precision to be discovered, whereas things like the Basher-Blocker-Turnaround / Cancel do.

As a side note: This level can be done without either trick

Then you're contradicting yourself, because that just goes to show how difficult it is to learn a specific trick, like the three-builder wall, from a level that provides enough degrees of freedom to do other stuff. Some players might walk away from this particular level knowing about the trick, others won't.

This is why I made the level "Stop and stair" deliberately without any other options, so that the player has no choice but to find out about this trick at some time.

[ccexplore]

To summarize what I said earlier:  tricks are not god-given, if nothing else there's always at least that one person who first worked the trick out on their own who (by definition) didn't rely on any kind of cheat sheets, tutorials or demo levels.  At the same time, just as there are walkthroughs out there for the entire game of Lemmings, I think it's fine if people want to post cheat sheets and demo levels for benefit of people who preferred not to always work everything out on their own.  Just as it's fine for other people to ignore such things altogether if they do prefer to figure things out themselves.  I can sympathize with the issue that some relatively advanced tricks may have ended up being used in quite a number of custom levels rather than just a few, and thus can end up standing in the way of a lot of levels for some players.

As a side note: This level can be done without either trick

Then you're contradicting yourself, because that just goes to show how difficult it is to learn a specific trick, like the three-builder wall, from a level that provides enough degrees of freedom to do other stuff. Some players might walk away from this particular level knowing about the trick, others won't.

You're assuming that the level is intended to be solved only with that trick, and that it is intended to teach that specific trick.  I'm far less certain that's the case.  I don't remember exactly what I did when I first played and solved that level, but I think I worked more along the lines of simply spamming enough builders and other skills to merely delay the lemmings that would've turned around, rather than explicitly creating a wall with stacked builders.  Indeed, as far as I can remember there really isn't any official level in Lemmings 1 that require (or even merely heavily recommend) stacking builders to solve, in contrast to other techniques like digging/mining a holding pit that gets reinforced throughout multiple levels.

I do feel that the level in question may be slightly inappropriate (harder than normal) for the ranking and position it is in, especially given the relatively small amount of space to work with and the maxed out release rate.

I think it's naive to think that just because you provide a cheat sheet of tricks, that would be enough to keep players from "walking away" from any particular level.  Sometimes you just get mentally blocked regardless, and with enough frustration people will walk away or at least set aside a level.  At the same time, if there's a trend of certain tricks getting used in a lot of different levels, it seems good to have a backup option that some players can choose to use to unblock themselves.  Just as there's value in having walkthroughs of games on the Internet even as some people don't need it and would actively avoid it.

[grams88]

A lot more to blockers than meets the eye.

Going back to the atari st two player I certainly remember the fake blocker if that is the same one you were mentioning Strato. it became a massive hassle trying to get by them, I thought it must of been a glitch of some sort. I remember one level my dad was like what on earth is going on there. A fake blocker on a level like (Take what you can when you can) can be a disaster, if anyone else remembers that level.

[ccexplore]

Finally read the description for "fake blocker".  If we're being technical, it's not that the lemming never transitioned to blocker.  Instead the transition to blocker and then to walker/faller all happens on the same physics update cycle, and the display isn't refreshed any faster than that, so you cannot see the intermediate blocker state displayed.

I'll say this is definitely a super technical trick, and essentially relies on the fact that sometimes a lemming can be arranged to be effectively (even if only very momentarily) standing on mid-air per actions of other nearby lemmings.  The stated basher variant in particular is super-precise and therefore not generally a trick I'd like to see become too widespread, outside of challenges and levels specifically designed to be of challenge difficulty.

Incidentally, I wouldn't really consider the digger-blocker turnaround to be "fake blocker", even though I know it technically fits with your particularly phrased criteria.  In that case you most definitely see the blocker being turned into a blocker, and generally he isn't immediately freed by the digger's action either.

The more general conceptual idea of taking advantage of intermediate states of a skill action (eg. a bash stroke or a dig stroke), and to have other lemmings skill assignments be taken during those particular intermediate states, is a more general conceptual technique not specific to blockers.  The player should learn on their own to generalize these concepts a little, rather than expecting every possible specific variant of the concept (like those listed cases of "fake blocker") to be always available in a cheat sheet or demo level somewhere (though I imagine sooner or later people will probably manage to exhaust the possibilities and have most variations be documented or demonstrated somewhere).