Dr. Flumph's Instant Bridge

Choose a spot within range. You throw the miniature bridge, which expands in that spot to be as much as 200 feet long and 10 feet wide, 100 feet long and 20 feet wide, 50 feet long and 40 feet wide, 40 feet long and 50 feet wide, 20 feet long and 100 feet wide, or 10 feet long and 200 feet wide. The bridge is 3 inches thick, and each 20 x 10 ft. panel has AC based on the material you used to make the bridge (See DM’s Guide) and 100 hit points. The bridge can hold any amount of weight for the duration.

In a pinch, if you don’t have a miniature of your favored bridge, you can use a sliver of any other material or any object. Its size and shape are based on the object, and its thickness is the correct proportion. A dagger would be dagger shaped, up to 100 feet across and the blade begins as 20 feet wide and tapers down, or it could be placed sideways. A coin would be shaped like the coin, being as large as 45 feet in diameter (circular coin) or a 45 x 45 square (square coin), or whatever the shape of the coin may be. A splinter would be shaped like a 200-foot long giant splinter, and so on.

The issue with using something rounded, such as a rod, a staff, a stick, etc. is that it might roll, if only a little bit. A creature crossing such an object must make a Dexterity (Acrobatics) check DC 10; on a failure, the object rolls a bit and they must make another check, this time DC 15. If they fail the second time, the creature falls off.