It usually starts at 8 pm every Wednesday evening with a pizza break. When Howard was otherwise engaged, the guys eventually got Penny to take his place and proved to be very talented at Halo. She "killed" Sheldon at least three times, once with a Covenant Plasma Grenade and another with an Incendiary Grenade. Sheldon was known to be both a sore loser and a cocky winner.
The next after Howard rejoined them, Penny and her friends walked in on the group and said " Hey guys my friends and I got tired of dancing so we came here to have sex with you." The guys continued playing completely oblivious to what Penny had just said.
It should also be noted that some Halo game mechanics employed during episodes in which the characters play Halo are inaccurate. Penny asks once, "Hey, whose head did I just blow off," after joining the guys in Halo night. She also comments, "Look Sheldon. It's raining you!" Both the statements can't be brought about logically because in no Halo game to date can opponents be dismembered in any way. The dead characters in Halo however can be flung or "tossed" by large explosions, so this could be the case. It should also be noted that the sound effects attributed to the plasma grenade explosions are inaccurate.