Vampiric Sliver — ruling 1

Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn’t provide any additional benefit.

Vampiric Sliver — ruling 2

If the creature type of a Sliver changes so it’s no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.

Vampiric Sliver — ruling 3

If a Sliver has this ability when it deals damage, but not when the damaged creature is put into a graveyard, nothing happens.

Vampiric Sliver — ruling 4

If a Sliver doesn’t have this ability when it deals damage, but does have it when the damaged creature is put into a graveyard, the ability will trigger.

Vampiric Sliver — ruling 5

If Vampiric Sliver is put into a graveyard from the battlefield at the same time as a creature dealt damage by another Sliver, the Vampiric Sliver’s ability will trigger for the other Sliver. That Sliver will get a +1/+1 counter.

Vampiric Sliver : règles, fonctionnement et interactions (MTG)

Vampiric Sliver is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

All Sliver creatures have "Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature."

How it works : Vampiric Sliver

Original English text — Wizards of the Coast / Scryfall

#1July 1, 2013· Wizards of the Coast
Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn’t provide any additional benefit.
No other card is named in this ruling.
#2July 1, 2013· Wizards of the Coast
If the creature type of a Sliver changes so it’s no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.
No other card is named in this ruling.
#3September 25, 2006· Wizards of the Coast
If a Sliver has this ability when it deals damage, but not when the damaged creature is put into a graveyard, nothing happens.
No other card is named in this ruling.
#4September 25, 2006· Wizards of the Coast
If a Sliver doesn’t have this ability when it deals damage, but does have it when the damaged creature is put into a graveyard, the ability will trigger.
No other card is named in this ruling.
#5September 25, 2006· Wizards of the Coast
If Vampiric Sliver is put into a graveyard from the battlefield at the same time as a creature dealt damage by another Sliver, the Vampiric Sliver’s ability will trigger for the other Sliver. That Sliver will get a +1/+1 counter.
No other card is named in this ruling.