Color Block Jam Levels 600–700: Protect the Center Junction

Why is the center important?

An intersection can serve as a turn, staging space, or passage for several colors. A block that appears finished can still occupy that junction and remove access from a later route.

Which route should use it first?

Trace all destinations touching the junction. Give priority to the route with the fewest substitutes, then keep the other approach visible. Do not fill the junction while the dependency is unresolved.

What if the junction is already blocked?

Find the smallest move that clears it without creating a corner trap. If the board cannot restore the needed route, undo to the first placement that consumed the intersection.