How to make a big world map like Ark without lagging for all the stuff in it?

Hey guys im trying to make a game with a big map, however once my character goes in play it has a lot of lag because of all the things on the map! how can i make it so I have a big open world like an mmorpg or like ark without causing gameplay issues

A lot of things. 1 would be to use level streaming, which basically means is that your one level will be made of several “child” levels that can each be loaded seperately based on where the player is in the game. Another thing would be to add lightmap importance volumes anywhere the player will be, and only use shadows with lighting when its absolutely necessary. 3. Dont use the open world demo. I know its tempting, its free and theyh look great, but they will lag the hell out of a game on the bestest most expensive gaming rigs. 4. you can turn down the material and quality level in the settings menu (i think by default everything is set to epic). 5. erase unnecessary foliage. sometimes 5 blades of grass can be used in patches that currently have 50000 of them. Thats everything i can think of off the top of my head, but theres definitely many many other ways to tone down the lag

If you were talking about using the Ark modding feature from the epic games launcher, Its almost always going to be laggy. Theres just so much stuff, the more you play it the more your computer will get used to it and lag a little less and less over time, but it will lag