Bases

are places that you create by mining resources and placing blocks to make a base where you/team can stay in. They do not spawn naturally on the map and you have to make it yourself. They can look any shape or size and can have anything inside them

Creating

 * When making your base, if you are not in a team, you should first get the materials needed. This means you need a lot of wood, stone and (in case anyone attacks).
 * You can use any blocks but most people use: Spikes, traps, Stone Walls/Wood Walls, and Turrets(Mines if you are in Sandbox).
 * To gather resources, use stick, daggers, or hand axe. After you make it, put own a spawn pad, die on purpose, and you spawn in your bases. You can then level up again and acquire stronger .(not needed in sandbox)
 * A base needs to be easily defended and needs to be able to have an entrance and exit (it could be just one way).
 * A good way is put your base at the corner of the map, or at the edge of a map near a river, and make one way in. This means they can only come through one side.
 * Use a Hunting Bow and its upgraded forms, as you can shoot people over the walls
 * Make a lot of layers of stone walls.
 * Then, you make on way in, guarded by an whole line of traps. After, you put turrets on both sides of the door. The means that the player who try to invade you bases have to mine up to traps, go through the walls, or get stuck in a trap, which take a long time, so you get stuck time for your turrets to shoot. The only foolproof way is if they are already wearing Emp hat, because they cannot put it on when they are trying to get through because it is way too late.
 * If you are in a team, make your bases with the team, to get max resources, max defense and an overall stronger base.
 * If you are making it as a team, make sure the turret are yours in case you decide to leave, or if someone betrays you and your team.
 * If you are designing a base, use sandbox. Just don't go over the normal limits: 2 turrets, 30 walls, 1 spawn pad, 7 windmills, and so on
 * Finally, it is always a good option to have a retreat. Ideally add a back-up Teleporter, or make a way that is easy to retreat (e.g.: in the river with Flipper Hat equipped, or the Snow Biome with a Winter Cap. Putting yourself in a place you cannot retreat from is a one way ticket to death.

Against
If you are trying to invade someone's else base, or just annoy them, or for revenge, try this:
 * Wear an Emp Helmet to stop turrets hitting you, and use a Great Hammer to break traps and walls.
 * Shoot through their walls, since Arrows can go over walls.
 * Use Samurai Armor to mine down on their defenses faster.
 * Just make sure you have something to block the turrets from shooting at you.
 * Bring your team if you have one: more people, more power.
 * If there is only one entrance into the base, put a stone mine in front of their entrance and exit if that if there way in and out. They will have to mine down the walls to get out, or kill themselves.
 * Make sure you have lots of, because a base is meant to be defended easily, and they will harm you. You need to food to heal.
 * Make sure the intervals between food consumption are reasonable, otherwise you will get the Shame! hat.
 * Bring something that will make you move faster, if the retreat option is necessary. Monkey tail, shadow wings, booster hat and if you need to cross river, wear flipper hat. With arctic, wear winter cap.
 * Finally, if you manage to defeat the person, destroy their Spawn Pad, so they don't spawn back in their base.
 * You can also get the resources to change the player's base into your own design so you can live in it. When they come back, they will have to invade it all over again
 * If all else fails, pretend to join their team. Go inside their base, and once you gain their trust, kill them.
 * This is generally looked down upon; unless you're hungry for revenge, try other alternatives.