# logic problem/puzzle solving

I'm here to ask you if it is possible to find a way to solve this problem. I'm designing the puzzle-enigma section of a video game and try to find possible solutions and mechanic for it.

Imagine each circle in the pic below is a platform and the rest of empty squares is void. Only the first platform is active and "usable"(say you can step on it). You have six characters that have to go from one side to the other stepping only on the platforms and each platform admits one to six characters a time. Stepping on a platform instantaneously make appear the following one; however getting off it instantaneously deactivate and make disappear the following one (making eventually die a character that would be on it at the moment of the deactivation).

Is it possible for the six characters to get to the other side all alive?

The only solution I found for the moment was to change the rules of the puzzle, making each platform activate the following AND the previous one; like this, you would have the six characters one on each of the first six platforms and the bottom one going time by time to the top one.

Another idea I thought about was: each character on each platform activate one link, so two characters on one platform activate the two following ones,three characters on one platform activate the three following ones and so over, but I couldn't find a solution like this either.

Any suggestion?

Thanks for your time guys, cheers!

• with those rules, the last character can never leave its square, and therefore you can only have 6-len+1 alive characters at the end (where len is the size of the path.) All the other are stuck – njzk2 Jan 12 '15 at 20:12
• In your particular example, there is a shortcut, but taking the shortcut causes every one to die by propagation of disappearance of tiles. – njzk2 Jan 12 '15 at 20:12
• How are you planning for your characters to discover these rules? The hard way with restore from a save point, or by logic etc? – Callidus Jan 13 '15 at 9:27
• @Jacopo: Isn't it fun to see your work done by somebody else ? (Just joking, I actually like the question very much.) – BmyGuest Jan 13 '15 at 11:43
• Is the gridsize 6x10 and the drawn path already a given? – BmyGuest Jan 13 '15 at 11:44

All that matters is the chain, and so far your rules are quite local. If you can get a couple steps in you can get all the way. Maybe different characters can step different numbers of platforms? For example, one might be able to go forward $1$ or $3$ spaces or back $2$. Maybe each platform can only be used some number of times? It becomes a maze in a bit of a disguise.

• what you mean by if you can get a couple of steps in you can get all the way? – jacopo Jan 12 '15 at 18:58
• If you can get the whole party to say the third platform, you can use the same process to keep going. This is because with the rules you suggest no platform impacts ones far away. Maybe you want it to. – Ross Millikan Jan 12 '15 at 18:59
• yep thats it. I want it to be tricky but not too much. for the moment i think the only valuable solution is making them activate the previous and the follwing one and add some enemies coming, making each one player responsible for all (if one dies, he deactivates his platform and all the others do in chain). – jacopo Jan 12 '15 at 19:05
• It depends on the set of rules you choose. The first rule proposed is not going to work because character can stand on a platform if and only if there is a character standing on a platform behind it. Now, this can't work even for a chain of length 2, since the last character would kill oneself by going forward. In second suggestion, the problem is trivial since you only need your characters to occupy 2 adjacent platforms so they could move as group (you need 3 characters to perform this). The problem with the third one is the same as the first one, the last character can't survive. – Ennar Jan 12 '15 at 19:11

What about using 6 * X platforms and let different characters see different platforms(either from the beginning or during walking)?

For example, all characters step on the first platform because the orange character can see it. After this they can see the second platform (also orange). Next one is the green character that can see the platform ahead and so on... So the player has to collect information from all characters before (s)he can follow the path.

• I think the idea is good, but can it be implemented? (i.e. it depends on the game if "what player sees = what each/all character sees") – BmyGuest Jan 13 '15 at 11:42
• If each character was a human player on it's own, success would only be possible through jolly cooperation. If, however, there was one human player using all the characters then the player could see everything and has to do some puzzling. – Avigrail Jan 13 '15 at 11:52
• for 1-player: Wouldn't it be simple "move all players except player at which the platform become visible move forward to the next platform"? Not very challenging. But I guess a bit challenging, so maybe exactly what is needed after all... – BmyGuest Jan 13 '15 at 11:56
• We will have to wait for the OP to give further instructions. – Avigrail Jan 13 '15 at 12:48

I suspect this is for a pathfinder/d&d game or something similar. I've been thinking of a similar puzzle but I haven't had to worry about putting it into practice yet.

My suggestion would be to give each tile three "stages" -- cursed/trapped, normal, and hollow. The first stage, "cursed", would have some kind of negative effect if stepped on (say, it turns the person to stone). The normal tile is a normal tile. The hollow tile stage just simply means it has disappeared (causing any petrification victims to fall to their doom and shatter).

If you make it so that stepping on a tile changes the stage of the four adjacent tiles (cursed > normal > hollow), and once a tile goes hollow, its gone forever (or until the puzzle is reset). That might make for a better puzzle.

I haven't tested it yet, but when I get home from work, I can certainly build a program in Flash that we can use to play around with it and see if it works.

# Can it be a puzzle to get one character across only?

(Who can then pull a lever or such a thing to make a safe path for everybody else.)

This might make for a more interesting puzzle...

I think I have found an interesting puzzle inspired by your question, but I'm not sure it is solvable. However, we are on PuzzlingSE, so lets find out...

I've posted it as this puzzle here.

If it works out, I think it's actually a really good puzzle ;c)