troggnostupidhs
commented
5 years ago It is a general issue that cards with CANT_PLAY tag can be played but have no effect. It is currently only possible in Adventure and Tavern Brawl.
CANT_PLAY is intended to indicate to the AI that the card shouldn't be played. If a player has the card it should be unplayable (or autodiscarded or something), visually different (strikethrough text to indicate there is no effect), or playable as normal (since CANT_PLAY is for the AI).
Jetz72
The Lich King: Cards with CANT_PLAY tag can be played but have no effect
Arguably they shouldn't be played or have some indication that they have no effect whatsoever.
https://www.youtube.com/watch?v=785k-oKCI4Y
Note this also negates battlecries, which are usually still activated in graveyard.
Icecrown & Boss Battle Royale: Sindragosa's Unchained Magic does not trigger effects if the opponent has no spells
Unchained Magic - 1 Mana Spell, "Deal 3 damage to the enemy hero for each spell in their hand."
https://us.battle.net/forums/en/hearthstone/topic/20769537187
(Screenshots rule out all the usual suspects. Board not full, no Counterspell, no minions appear to have died)
Upon further investigation, this spell seems to have the AI_MUST_PLAY tag set on it at all times. But Sindragosa will never use it if the opponent has no spells. This is because it evidently has the ability to detect whether the enemy hand contains spells, and it applies a CANT_PLAY tag to itself if there are none. As described in issue #996, the CANT_PLAY tag prevents the AI from using them, but they can be "used" by the player. If played, they will be immediately destroyed with no effect, as though they were countered. This usually doesn't matter for Unchained Magic, since the only time it would apply is when the spell text would have no effect anyway. However, it evidently also prevents effects that react to it from working.