Blue's Handy Dandy Passage of Safe Travel

In order to cast this spell, you need to draw a symbol with the chalk on a flat surface at least 5 ft by 5 ft wide. The cost of the material components increase by 500 gp for every 5 ft more that the original 5 ft by 5 ft. In an sphere with a radius equal to 5 times the length of the surface centered on the location where the surface is, teleportation spells can connect to another area where you cast this spell, provided that you cast the spell covering the same area. Teleportation spells in the area that can teleport you more than 100 ft have that distance extended to 1 mile, so long as you are teleporting to the other location. In addition, it expends a spell slot of one level lower that the level you would be casting it at (a first level spell still takes a spell slot of first level). Finally the spells duration is doubled, and increase to 1 minute if it is less than that. When casting a teleportation spell normally while in the radius of the spell, there is a 10 percent change that you are teleported to the bound location instantly without any other effect.

At Higher Levels: When cast at using a 9th level spell slot the teleportation spell used to activate takes you to the corresponding location without any regard for distance. In addition, if you use a 9th level spell slot, the spell can transport you to another plane of existence.