Heyo! I am here to ask a question how to create a live event like fortnite?

Hi this is quite simple you use os.time. There is a good video on this made by someone called alvin blocks on youtube

You can use os.date to set the hour of the event. Look this script:

local function event()
--event code
end
while wait() do
    local Date = os.date("!*t") --Get UTC date
    if Date["year"] == 2020 and Date["month"] == 7 and Date["day"] == 20 and Date["hour"] == 14 and Date["min"] == 30 then --Change the time values to the ones you want the event to happen
        event()
    end
end
end

To make for example explosion effects, use particle emitters. You can insert a particle emitter with the smoke texture id and another one but with the fire particle id. Website for those particles.

Smoke particle: https://www.roblox.com/library/446970590/Smoke-Particle

Fire particle: https://www.roblox.com/library/242911610/PARTICLE-Fire

Change the color of each particle to the one you want to. To destroy cities, dupplicate the city and place it in the ServerStorage. Then, make the city destruction by elimintaing houses or if you want only to destroy some parts of that house, simply use NegativeParts and Parts, then make a UnionOperation with those parts eliminate zones of the building destroyed. To add realism, you can make parts, change its color to brown and its material to Wood planks to simulate a wood plank that was blown during the explosion. If you want to fix the collision system, go to the Union properties, find "CollissionFidelity" and change it from default to PreciseConvexDecomposition. Once you finish the destroyed city, place it in ServerStorage and place the normal city again in Workspace. To add the destroyed city into the workspace during the live event and eliminate the destroyed city, do this:

game.ServerStorage.DestroyedCity.Parent = game.Workspace
game.Workspace.City.Parent = game.Serverstorage

Change "City" to the name of your model and "DestroyedCity" to the name of that city destroyed. I hope this helped!