Tagging refers to a mechanic for drop and experience distribution. Monsters come in two varieties: taggable and untaggable. Taggable monsters will award experience and drops to the first player to attack them. Untaggable monsters will divide the experience based on damage dealt by each player and generally give the drops to the player who dealt the most damage.
Monsters that can be tagged will display an asterisk (*) next to their name when attacked.
Until a patch on March 11, 2019, the Tuska's Wrath ability used on non-taggable slayer targets (mainly Nihils, Muspahs, and Glacors, did not act as the powerful 100x-Slayer-level-attack, even on-task, and instead as the less powerful base attack. Now, Tuska's Wrath acts the same on these three creatures as on other Slayer creatures.