13. 19 round. In epic mode, the total game time is 1000 rounds, while in standard mode, it is 400 rounds, and the game time is 2.5 times faster than that in standard mode. Minus 4000 BC, the number of rounds needed to reach 2050 is 2 1 10 years. In the standard mode, the number of rounds required to reach 2 1 10 year is 2 1 10 year divided by 400 rounds, which is 5. The number of rounds needed to reach 2050 is 5.275 rounds multiplied by 2.5, which is equal to 13. 1875 rounds, and the two decimal places are 13. 19 rounds.