I am not sure why I picked up this game that late, but my friend recommended it, so...

I am pretty cool with the early in-game recommendation to spare as much as I can so I am going for this approach. Currently, I am at the (first. I don't know if there are more. Don't want to spoil myself) boss fight with Undyne. So far into the game, I have a consistent feeling that every monster behaves very differently in terms of the criteria to spare. It started off acceptable, but it is getting annoying now, for a few main reasons:

  • There is almost no hint at all (of course the yellow name wouldn't count). The behaviors are meant to be amusing, instead of following any logic.
  • There are all sort of actions that need trying out, including the most insensible ones (e.g. flee). Not only that, some even require repeating certain actions many many times, and even worse, the order sometimes matters.
  • Once you (if at all) get hold of the behavior of that monster (or in particular, boss), it is meanwhile likely the last occasion where it is useful - the pattern learnt will not be useful at all after that monster encounter.
  • (My fault) I do not like seeing that GAME OVER scene over and over again... It certainly doesn't make me stay determined...

I have a feeling that from this point onward, I would need the help of walkthroughs more and more frequently, and this is pretty discouraging.

So, I am just wondering if I am missing any essence of the game that is meant to guide me through and get me out of this totally trial-and-error approach. Is it that many conversations and side-missions (are there? I came across a lot of irrelevant stuff but don't know what to do with them) are actually giving hints on monster behaviors during battle? Or an in-game library that I have missed out that talks about these things? Or anything an experienced Undertaler could recommend to me?

  • That's definitely what I did; but now you've got me interested to know if there actually was a better way to deal with that.
    – JMac
    Apr 1, 2020 at 20:19
  • I believe the no-kill approach gives a "Mercy" achievement in this game? Lots of people ask about how to do this, I don't think it's the easiest path for a first play-through. It's more a path for veteran players who want to challenge themselves. There's also a "Genocide" achievement where you do the opposite and kill everything, I believe.
    – Kadima
    Apr 2, 2020 at 13:42
  • @Kadima. Strange enough, the plot of the game successfully led me into the deep belief that sparing everything is the only "correct" way to play the game (while, with reasoning, knowing that it is unnecessarily the case). The recommendation for one, but also all the kindness and innocence well demonstrated by all monsters. More experiences only reinforce this belief. Apr 2, 2020 at 15:40
  • @Kadima Interestingly enough, the "True Pacifist" run cannot even really be completed on a first playthrough. To get that ending, you actually have to first have a neutral run completed (i.e. you can kill some monsters, but not enough for the "Genocide" effects to take over). If other players are like me, they likely tried to be as pacifist as possible during their first run; but missed a couple key things for a neutral ending anyways.
    – JMac
    Apr 2, 2020 at 15:51

1 Answer 1


There are often times hints inside either the dialogue of the monsters or the "Check" action that indicate the types of things that need to be done to pacify a monster. In addition I should note that in non-boss encounters you need not spare the monsters to still complete no-kill run simply running away is usually faster and can skip some of the puzzle solving aspect. Beyond that there is quite a bit of trial and error too figure out exactly how too pacify a monster.

There are no major side quests in Undertale (with two notable and obvious exceptions) but there are a number of monsters you can talk too and interact with that are tangential to the plot/game.

  • I will also note that you can run from Undyne unlike the other boss monsters which is notable.
    – Toron
    Apr 3, 2020 at 20:13

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .