Question 1

What do the pipe shapes mean?

Accepted Answer

Straight pieces join two opposite sides, elbows join two corners, T-pieces three, and a few four-way crosses exist too.

Question 2

Does water flow backwards?

Accepted Answer

Flow is recalculated from the source every click, so direction never matters u2014 only connection does.

Question 3

How many boards are there?

Accepted Answer

Unlimited u2014 each solved board generates a fresh connected layout.