Join this expedition, and you will have the unforgettable opportunity to explore Sumatra, from the top of its majestic volcanoes to the depths of its tropical rainforest. Find the most exotic animals and the most exuberant flowers, and discover the endless variety of cultures that coexist on the largest island in Indonesia. Your expedition sets out with the mission of writing a travel notebook that will help raise awareness of one of the richest ecosystems in the world. Whoever makes the best contribution to this exciting mission will win.

In Sumatra, players move around the island to explore its multiple landscapes. On a turn, your possible actions depend on where you're located in relation to the travel notebook token that starts the game in base camp with all the players:

If you're one space behind the token, you move to the notebook's space and end your turn.
If you're on the same location as the token, either you move ahead one space or you stay put, take a tile from the pool of "available information" tiles, and add it to your personal notebook.
If you're one space ahead of the token, you move the token to your space, move all the "available information" tiles to the "known information" pool, draw tiles from the bag equal to the number shown at your location, add those tiles to the pool of "available information", then take one of these new tiles and add it to your notebook.
Thus, you're catching up with the group, researching with the group to add info to your notebook, moving ahead, or digging into new tiles ahead of everyone else.

Tiles score and have effects in various ways, for example, with players gaining or losing points for meeting the most or fewest inhabitants. Flora and fauna tiles score only if you have a pair in a column, but only the highest-valued of this pair scores. Villages score only if you have more pairs of reception and GPS tiles than the number of villages, while the reception and GPS pairs net you no points, but allow you to get a tile from the pool of "known information". Equipment makes it safe to explore volcanoes on the island, and if you don't have enough equipment, you might lose other tiles you've collected.

Sumatra also includes badges that players can collect. Be the first to collect, say, three flora tiles or a combination of two inhabitant and two craft tiles, and you can claim the badge for this, which is worth 3 points at game's end. You can also claim one diversity badge for having at least one tile in at least six rows of your notebook. The more rows you have a presence in, the higher the value of the diversity badge, but you can claim at most one during the game — and if someone else claims the six-row badge, then you'll need to have a tile in at least seven rows for the next one...