How Do I Spare Undyne...

[woodman >:]]

Please Help Me...

[strata_ranger]

Undyne will never accept your mercy as genuine. Ever. (She even says as much, if you try to Spare her.)

You cannot avoid facing Undyne in battle, but you CAN avoid killing her -- you will simply have to find another way out of battle than attacking. Undyne even drops a few hints about it, so make sure to explore all of your options.

ALL of them.

[Pegasusangel]

Ditto to what strata said. Remember red stop signs...I mean blue stop signs....just pay attention to what is being said. ;) That’s about the best tip I can give you.

[♢ sneeper ♢]

Keep sparing her untill there is an option to run, then run. Thats all i'll tell you though.

[Radiocaster]

Once your soul turns red flee

[Ruke (Soreasan)]

Complete the genocide route, and then walk 5 circles around Sans before resetting. When you begin a new game, make sure you buy 1 spider donut and go back and eat two candies. When you come to Undyne, your terrible breath will make her gag, giving you the option to spare her mercy from your breath.

Alternatively, there is a water fountain when you arrive at Hotlands whereupon you can grab the entire cooler and dump it on her. By doing this, you unlock the betrayal kill where you soak her and she turns into fish mode.

[Pegasusangel]

Wow that last post reminded me so much of the how to get mew tricks floating around the Internet in 1998 lol.

[woodman >:]]

Thanks.
Now I Know That Killing = Mercy. Think Of Blue/Green Shelds.
Save Your Fricking Life.

[woodman >:]]

Undyne is a fricking LOSER.

[strata_ranger]

It may help to remember that the only way to kill a monster is through the FIGHT command. If you don't see damage numbers appear on a monster's HP bar, this means whatever you tried did not actually harm the monster, nor can that action kill them.