Tutorial 5

This is not a challenge, it's an exercise to illustrate new tricks for beginners to advance their skills!

For more tutorials, see here.

This tutorial is about how blocks that can normally be walked on, can be turned into no go areas. The trick is to push an eye block vertically against the target block. This engages the Evil Eye effect. To restore normal operation to the target block, simply move the eye block away from it.

I don't know who first discovered this effect. If anyone can come up with a relevant link, please let me have it so that i can include it here.

There are many ways to implement this effect in a design, and we'll look at just a few in this tutorial. Hopefully, designers and players alike will enjoy ..



Location A - Using a slider is the most straightforward method. Notice how the slider constantly pushes the eye upwards against a stone block, preventing both B and R from reaching the win. This particular configuration, featuring a permanently inaccessible win, can be used to create a red herring and requires a reachable win somewhere else in the puzzle. But permanently inaccessible blocks can be useful in other contexts too .

Location B - This is one of many ways to disengage an Evil Eye. The first slider engages the eye, while a second slider is poised to force it down .. but only when the player pulls away the free draggable. In practice, the mechanism might be hidden and a rod employed instead of a free draggable; or the disengagement could be a secondary effect of some other action, as a subtle twist in a puzzle. For now, let's pull away the free draggable so that B can pass over the brick block and join us as we proceed.

Location C - We don't always need a slider to engage the Evil Eye, even the eye on a bot works! The arrangement at C is designed to encourage R upwards with a stair block, while hemming him in with the grass blocks and the target block itself, an upside-down stair block. This is pretty stable, but R has occasionally been known to get himself free! There are plenty ways to use an R bot's eye, don't be limited by this one.



Location D - Even B's own eye can be used! Send him to the elevator and raise it one block so that his eye touches the wedge above him. If you choose the right moment, you'll be able to direct R onto the win. But then be sure to restart the tutorial .. because the best is yet to come!

Location E - Here is an arrangement that automatically toggles the Evil Eye off 25% of the time. As a designer, you can tune it by adjusting the number of metal pillars on the rotating motor.

Location F - Another auto toggle mechanism. This one exploits an interesting quirk of the rotating motor. A motor has 4 evenly spaced corners that jut out .. just enough to briefly disengage the Evil Eye as they scrape against the metal half pillar. The bent pipe on the motor is for those who want to examine the workings closely.

Location G - This arrangement showcases a way to intermittently interfere with expectations for an autopilot instruction. There's quite a lot going on here, so here's a close-up..



• First, the frequency can be tuned by the number of vertical pole segments used for the disengagement slider.
• Curiously, with only one horizontal pole on the slider, it gets stuck -- the second horizontal pole somehow ensures that the slider rises again!
• Anyway, the whole point is this .. when the Evil Eye is disengaged, an autopilot setting to the win block will follow the blue route as one might normally expect. But if the autopilot is set while the Evil Eye is engaged, B will be shocked to find himself following the red route instead!
• Finally, the designer might be tempted to provide a visual clue to flag when it is safe to set a blue autopilot route (especially if the Evil Eye mechanism is hidden), by means of the second vertical pole-and-slider mechanism at G. But notice that the two vertical sliders fall out of synch due to the disengagement action of the active sliders, requiring a more carefully thought-out and well tested hinting plan.

Conclusion
These techniques are just the tip of the iceberg for the Evil Eye. With a bit of imagination, and used wisely, designers can bring new levels of enjoyment to the game. And, equipped with an understanding of what might otherwise be mysterious behaviour, players can prepare themselves for great fun!

Check out these puzzles for some clever implementations of this effect...

• Best Buddies - by @Star Penguin.
• Hard Choices - by @Don G Rowe.
• Eyes Open - by @trids.

Also, don't miss Evil Eye Fails, where @D.S.Masters explores a few twists in the tale!

perfect tutorial I didn't know half of these.

Very interesting tutorial for creators....and playersThanks for sharing @trids

@trids Thank you for another excellent tutorial. This is really helpful, .

Thanks folks .. please let me know where you come across the Evil Eye in puzzles, as I would like to include links to them for inspiration.

I used one in one of my early levels Hard Choices:
https://mekoramaforum.com/media/hard-choices.7009/?page=2

Thanks @Gepeto! Was it one of your puzzles that I'm trying to recall? Haven't you used the Evil Eye in some of yours?

there's still many tricks I need to know.. thanks for sharing @trids

There was another level by @Star Penguin (I think that's who it was) that used the Evil Eye, but I can't remember the name of it - it wasn't "Best Buddies", though. Many thanks for the tutorial - I've always wondered how that worked.
Here's another one: "Witch Tower" by @cpw [https://mekoramaforum.com/media/witch-tower.6081/?page=2]
And another: "Sympatic Pillar" by @PvB [https://mekoramaforum.com/media/sympatic-piller.12839/]

Question: does the Evil Eye need to be on a metal block? If it's not meant to move, just as a hidden way to block a path, can it go on another type of block?

Never mind, I answered my own question - yes, the eye must be on a metal block, and that block must be movable so that the eye squishes against the block above it, otherwise it doesn't work.

@Jorz Even us 'old folk' are still learning...
(BTW, you usually don't rate a tutorial, but nobody will complain, either)

@D.S.Masters

Pretty much, but it would be more accurate to say that for the eye to be squished up, it needs to be on something movable. This means a movable metal block .. or a bot. I haven't tested any cases where the eye is fixed (on a non-movable block) and the walkable path itself moves down onto it (like a fallen disconnected-motor log, or an elevator bar or something) ... which would be interesting to try out.

@trids I just tried it and it works - an Eye on a stone block, a knockable lands on it, and B can't step on that one piece.