Blocking of cave entrances.
Outposts - are not permitted. You have 1 base per map and can use /suicide to use a spawn point to travel quickly around the map (you keep your items) and/or use a flyer to get somewhere.
Building in or around obelisks, artifact caves (including near entrances), ruins and bridges (minimum 20 foundations away). Check the wiki for the map you will be building on for any named ruins or exceptions on the map building rules.
Preventing re-spawns or building in resource rich areas for: Crystal, Obsidian, Rich Metal (>5 nodes within 5 foundations) or other Rare Materials (Black Pearls, Element Dust, Element Ore) - Use the ARK Survival Evolved community wiki to determine if you are going to build in a resource rich area for that map.
No blocking access to high traffic rivers and oceans (rivers you can get a raft in and out).
No reserving space through pillar, foundation or platform spamming to secure an area.
No building in or around wyvern, drake or griffin trenches.
No long water pipes connecting outside your base range or to the ocean - we have enabled placement of the S+ water intakes to get water from anywhere.
Preventing beaver dams or wild dino nests from spawning in a given area.