Voidslime

Activated abilities are written in the form "[Cost]: [Effect]." Some keyword abilities, such as equip, are activated abilities and will have colons in their reminder texts. Loyalty abilities of planeswalkers are activated abilities.

Wotc — January 12, 2024

Triggered abilities use the word "when," "whenever," or "at." They're often written as "[Trigger condition], [effect]." Some keyword abilities, such as afterlife, are triggered abilities and will have "when," "whenever," or "at" in their reminder text.

Wotc — January 12, 2024

An activated mana ability is one that adds mana as it resolves, doesn't have a target, and isn't a loyalty ability. A triggered mana ability is one that adds mana and triggers on an activated mana ability.

Wotc — January 12, 2024

Abilities that create replacement effects, such as a permanent entering the battlefield tapped or with counters on it, can't be targeted. Abilities that apply "as [this creature] enters the battlefield" are also replacement effects and can't be targeted.

Wotc — January 12, 2024

If you counter a delayed triggered ability that triggered at the beginning of the "next" occurrence of a specified step or phase, that ability won't trigger again the following time that phase or step occurs.

Wotc — January 12, 2024