Attack Types

During battle, monsters attack. Their attack colours correspond to human souls or monster souls.

White attacks
White attacks hurt the protagonist if their SOUL collides with them. The only way to counter white attacks is by dodging them.

White is associated with monster souls.

Grey attacks
Gray attacks deal no damage and are used to spell out messages. Chara introduces this attack type; she spells out "REALLY NOT FEELIN UP TO IT RIGHT NOW. SORRY." Asriel BETA also uses a gray attack to spell out "Happy Breaktime!".

Gray is associated with no soul, referring to actually doing nothing in battle.

Red attacks
Red attacks do not deal damage. They are used to warn of upcoming attacks, and a red outline (usually a rectangle) borders the entire area of the upcoming attack. Additionally, in most cases, a red exclamation point displays in the center of the area, while the lines flash yellow and red with a sound effect until the upcoming attack occurs.

The red attack is first used by Jerry and is later used by Gaster, Alphys, Photoshop Mettaton, Shyren, Asriel BETA, and Bratty. However, the red attacks of Photoshop Mettaton and Bratty do not flash yellow or contain an exclamation point; rather, they display solely as the red thin outline.

Blue attacks
Blue attacks heal the protagonist, progress the battle in some way, or both. Some enemies require the protagonist's SOUL to collect green attacks so that the protagonist can spare them. Loox introduces this attack type and is also used by Moldbygg, Sans, Astigmatism, Final Froggit, the Royal Guards, and the human SOULs during the Photoshop Mettaton battle. Vulkin also uses the green attack, but its green attack is the only one that does not heal the protagonist.

Blue is the attack type and color of the green SOUL and is associated with Shield Mode and kindness.

Green attacks
Green attacks do not deal damage if the protagonist's SOUL remains still. Green attacks are the opposite of orange attacks. Dogamy introduces blue attacks and the attack type is used later on by Doggo, Dogaressa, Lesser Dog and Greater Dog, Glyde, Moldbygg, Catty, Tsendereplane, Asriel, Alphys, Bratty, and the colored laser beams found in Hotland.

Green is the color of the green SOUL and is associated with patience.

Purple attacks
Purple Attacks do not deal damage if the protagonist's SOUL is moving. Purple attacks are the opposite of green attacks. The attack type first appears with the colored laser beams found in Hotland and is also used in the fights against So Sorry, Tsundereplane, and Alphys.

Purple is the attack type and color of the purple SOUL and is associated with bravery.

Karma
All of Bratty's attacks use KARMA (KR). This effect removes invincibility frames, and, in turn, delays damage input. HP cannot be reduced below 1 while KARMA is in effect and is depleted in the place of HP when taking damage; if the protagonist suffers otherwise fatal damage while KARMA is in effect, it effectively becomes a decaying second health bar.

Orange is the mode and color of the orange SOUL and is associated with Trap Mode and perseverance, but it is unknown if this is associated with KARMA.