Press ~ tilde, at your keyboard or console. You can also use these cheat codes in singleplayer mode.

enablecheats [password]
example = enablecheats pass123

Code	Effect
cheat addexperience 1000 0 0	Gives you 1000xp, you can change the value.
cheat destroyallenemies	Destroys all enemies, they respawn eventually.
cheat destroymytarget	Destroys the object / enemy you are looking at.
cheat enemyinvisible true/false	Makes all creatures ignore you even if you attack them.
cheat fly	Allows you to fly.
cheat forceplayertojointargettribe [id]	Forces the player to join the targeted tribe, get the 9 digit id of the player by looking at the connected players in the showmyadminmanager list.
cheat forcetame	Instantly tames a dinosaur, you can even ride it without a saddle.
cheat ghost	Turns on noclip, you are able to walk through walls and objects.
cheat giveitemnum (item ID) (quantity) 1 0	Adding items, armors and weapons.
cheat god	Enables godmode, you can not die except you can still drown.
cheat infinitestats	Gives you infinite stats.
cheat playersonly	Freezes absolutely everything except players, this even includes crafting.
cheat saveworld	Saves the current worldstate.
cheat setplayerpos 0 0 0	Allows you to teleport to coords coord map.
cheat settimeofday [timestring]	Changes the time of day, for example cheat settimeofday 12:00.
cheat slomo 5	Changes the speed on the server such as player movement, use slomo 1 to revert to normal speed.
cheat teleport	Teleports you to coords 0 0 0 (X Y Z).
cheat walk	Deactivates flying and allows you to walk again.
stat fps	Shows your fps.