Hey all.

So I am making a minigame and currently have everything working well untill it comes to setting up a timer.

Heres what I currently have

A scoreboard showing player's kills
A fake player whos "Kills" Starts at 300 and counts down 1 per sec (5 min timer shown on the score board)

I have gotten everything working fine.
scores get counted, timer resets, all is working well
UNTILL!!!!

I want to test for the timer to reach 0,
And after some reading online i found you cant use testfor on non-online players (my timer player)


How would I make it so that I can have a working timer, that will run a commandblock chain when it reaches 0?
I know about setting a "Dummy" ojbective, but can I do that as well as run a scoreboard for that and player kills?

Im new to scoreboards so not so Up TO Date with the tips and tricks involved