The quote makes it clear that any method of 'suicide' is no longer allowed in IEM matches including commands or jumping off of the map on Vertigo, a map set in a high-rise building.
Sometimes, a team deliberately dying or killing themselves has some advantages.
Dying to a molotov provides less money to the enemy team than if you die to their SMGs in a round where they are seeking to farm money, as seen in 2017 when Na'Vi played Team Liquid. They elected to die in flames rather than reward Liquid with extra money on top of a won round.
Under these new rules, 'tactical' deaths would be a violation.
It would also be hard to determine if a death was truly intentional or a genuine mistake. Top professional players have been known to fall off Vertigo by mistake due to the exposed ledges offering no way up if you slip off.
This is just one of the many reasons the newly-added map has been criticised by casual fans as well as Counter-Strike's best players.
No specific punishment is stated for those players found to be deliberately dying, nor is there any criteria for how it can be determined that the act was done on purpose or simply an accident by the player.
Nov 7 Edit: IEM have announced the suspension of the rule in question and this will no longer be enforced at IEM Beijing.
#IEM Rulebook update: We are suspending article â€œ7.10.7 - Suicide During Matchesâ€ effective immediately.â€” IntelÂ®ExtremeMasters (@IEM) November 7, 2019
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