it's sad that this post was made 7 years ago and i had no chance seeing it
out of curiosity, how would you all feel about a little undertale “reaction images” pack? with little cropped and sized down dialogue boxes like this:
now just imagine these, but way more – perfect for bothering your friends over your favourite instant messengers. if there’s any interest, i will upload them all!
if you’d like these to be shared, please show your support via likes/reblogs/replies, not asks! asks regarding this will not receive responses.
Toriel is arguably a difficult boss to defeat peacefully for new players who have no prior knowledge of Undertale. There is no visible indication in the battle that MERCY works for Toriel before killing her, which is why players may end up killing Toriel by accident in an attempt to weaken her and make the Spare option active. However, if the player fights Toriel again after killing her, there is interesting flavor text provided by the narrator when the Talk ACT is used.
The interesting flavor text is the last line. When the Talk ACT is repeated a second time, the same line is repeated but slightly altered.
This dialogue seemed to imply that fighting, and ultimately killing, could be an act of Mercy. While that is still a valid interpretation, the FIGHT option can actually be used to defeat Toriel peacefully.
To defeat Toriel without killing her, the battle only needs to progress. The fight will not progress by talking or by running away. However, as @uselessundertalefacts explained in conversation, selecting FIGHT and intentionally missing will progress Toriel’s dialogue. By using this tactic, Toriel can be defeated without ever using the MERCY option.
The seemingly unusual change in the flavor text for Talk actually makes sense in Toriel’s battle. While missing intentionally may not exactly be fighting, the FIGHT option can be used to progress the battle towards a peaceful conclusion.