Stats

Stats
An example of a common stats table.
Mechanic type	Gameplay Mechanic

Stats are aspects that affect encounters. Most stats increase as the protagonist's LV rises, although other methods can increase the stats.

HP

HIT POINTS. When you run out of Hit Points, you lose the game. Eating food will restore HP. The number to the right of your HP is your MAXIMUM HP.

Undertale Demo instruction manual

HP (Hit Points) is the level of endurance that determines the damage a monster or the protagonist can take before dying. The protagonist's maximum HP starts at 20 and only increases when their LV does. Resting at the Inn or MTT Resort Bedroom fully heals and raises the protagonist's HP to up to 10 points above its cap. HP can also be restored through consumable items, interacting with a SAVE Point, or absorbing green attacks in battle. If the save file is edited to obtain higher HP than normal, entering battle resets it to a maximum of 15 over the maximum for the current level, not counting the extra boost to max HP at LV 20.

An attack hitting the receiving party lowers their HP. The loss is dependent on the attacking party's Attack and the party of receipt's Defense. Upon reaching 0 HP, the protagonist's SOUL snaps in half and shatters, sending them to the GAME OVER screen and loading the last SAVE Point or autosave. If a monster's HP reaches 0, they disintegrate into dust and reward the protagonist with EXP and GOLD.

Increased HP also increases the amount of damage monster attacks deal. For each of the protagonist's health thresholds of 21, 30, 40, 50, 60, 70, 80, and 90, enemy attacks deal one more damage, up to a total of 8 extra damage per attack at an HP above 90. Some attacks, such as those by Mettaton EX, have additional points at which the damage dealt varies.

HP has been abbreviated for Horsepower or Hit Poodles from Aaron and the Dog Salad's info Checks respectively.

AT\ATK

Attack. Determines the strength of the FIGHT option in combat. The number in the () determines your weapon's power.

Undertale Demo instruction manual

AT (Attack or ATK traditionally) determines the damage output of the attacking party. The protagonist's base AT increases with LV and equipping a weapon. AT can be changed temporarily during battles with ACTs or consumables.

When the protagonist's AT is high enough, the protagonist can spare monsters without ACTing. This rule is true even of monsters that have a non-traditional sparing method: Toriel can be spared immediately, and the colored name and everything else shows if the total AT is 20442 or higher (though the game softlocks after doing so).

DF\DEF

Defense. Reduces the amount of HP you lose. The number in () denotes the defense of your armor.

Undertale Demo instruction manual

DF (Defense or DEF) determines the damage input for the defending party. The protagonist's base DF increases with LV and equipping armor. DF can be changed temporarily during battles with certain ACTs or consumables.

DF is subtracted from the damage output of the attacking party. The amount that damage to the protagonist is reduced by is 1/5 of their DF, rounded normally. This means that for every 5 defense (starting at 3) the protagonist takes 1 less damage. However, it cannot lower the damage that the protagonist takes to a value less than 1.

If a monster takes 0 or less damage from an attack, the attack's result is displayed as a "MISS", and negative damage values restore the monster's HP instead of damaging it.

EXP\XP

What's EXP?
It's an acronym.
It stands for "execution points."
A way of quantifying the pain you have inflicted on others.
When you kill someone, your EXP increases.

Sans in the Last Corridor

EXP (EXecution Points) are gained by killing monsters. When the protagonist accumulates enough EXP, their LV increases. In the Undertale Demo, EXP is gained by attacking and sparing afterward and not necessarily killing.

The acronym is designed to mislead players, as in most games, EXP stands for Experience Points. If the protagonist "kills" Napstablook, they lose one "experience point," which does not affect their EXP and serves as an early clue that EXP are not Experience Points, but a different stat entirely.

LOVE\LV

When you have enough EXP, your LOVE increases.
LOVE, too, is an acronym.
It stands for "Level of Violence."
A way of measuring someone's capacity to hurt.
The more you kill, the easier it becomes to distance yourself.
The more you distance yourself, the less you will hurt.
The more easily you can bring yourself to hurt others.

Sans in the Last Corridor

LV or LOVE (Level of Violence) increases HP and AT when it rises, and some levels increase DF as well. This acronym is also misleading; traditionally, LV stands for Level. Sans describes it as "A way of measuring someone's capacity to hurt." The protagonist starts at LV 1 and can rise as far as 20 in-game. LV can be set arbitrarily high or low via file editing.

INV

INV (Invincible/Invulnerable) determines the number of frames an attack cannot hurt the protagonist after they receive damage. It is a hidden stat that the protagonist can only increase through the Cloudy Glasses, Torn Notebook, and Temmie Armor. The former two items explain INV in their Info check.

Invulnerability is set to 0 during the fight against Sans thanks to his KARMA ability. The Cloudy Glasses' and Torn Notebook's INV-boosting utility is still present, but it is reworked for the fight:

• If only the Torn Notebook is equipped, damage is ignored once every five frames, and KR has a 50% chance to take longer to damage the protagonist.
• If only the Cloudy Glasses are equipped, damage is ignored once every four frames, and KR has a 67% chance to take longer to damage the protagonist.
• If both the Torn Notebook and Cloudy Glasses are equipped, damage is ignored once every three frames, and KR always takes longer to damage the protagonist.

SPEED\SPD

SPEED determines the velocity the protagonist's SOUL can move around the Bullet Board. It is a hidden stat that the protagonist can modify temporarily only through Sea Tea, certain ACTs, and in a fight with Vulkin when the SOUL is hit by its thunder attack.

Murder Level

MDR (Murder Level) is an entirely internal statistic that tracks the protagonist's progress through the Genocide Route. This statistic begins at 0 on every playthrough and is reset by a simple Reset. The murder level is accessed a few times in-game, notably to affect types of bosses encountered and boss activity (including whether or not the protagonist battles Sans), and to trigger the Alphys Ending variant of the Neutral Route.

Flags in the protagonist's save file are accessed and used to determine the choices the protagonist has made, and whether or not those choices fulfill the requirements for a complete or aborted Genocide Route attempt. Except for the murder level override, each step increments the murder level only if all of the requirements preceding it have been fulfilled. For example, if the protagonist has killed Toriel but did not exhaust the Ruins kill counter beforehand, the murder level remains at 0.

The line number listed below corresponds to the line number in the protagonist's SAVE file, i.e. 31 greater than the flag number.

Flag	Line	Setting	Action to set flag	Murder level set to...
202	233	20 or greater	Killed 20 or more Ruins encounters	1
45	76	4	Killed Toriel	2
52	83	1	Killed Doggo	3
53	84	1	Killed Dogamy and Dogaressa	4
54	85	1	Killed the Greater Dog	5
57	88	2	Killed Snowdrake	6
203	234	16 or greater	Killed 16 or more Snowdin encounters	7
67	98	1	Killed Papyrus	8
81	112	1	Killed Shyren	9
252	283	1	Killed the Glad Dummy	10
204	235	18 or greater	Killed 18 or more Waterfall encounters	11
251	282	1	Killed Undyne the Undying	12
350	381	1	Killed Undyne, in any form
402	433	1	Killed the Royal Guards	13
397	428	1	Killed Muffet	14
205	236	40 or greater	Killed 40 or more Hotland encounters	15
425	456	1	Killed Mettaton (NEO)	16
27	58	Must remain 0	Have not spared any mini-bosses, such as Lesser Dog

The murder level override is checked after this, ignoring the above calculation:

Flag	Line	Setting	Action to set flag	Murder level set to...
26	57	1 or greater	Must be set manually, by editing the flag or pressing M in debug mode	Setting

The protagonist battles Sans if the murder level is 16 or higher.

Stats Chart

Until LV 20, HP is calculated as 16 + (4 × LV), AT is calculated as -2 + (2 × LV), and DF is calculated as (LV - 1) ÷ 4, rounded down. AT and DF are also each internally considered to be 10 greater than displayed on the Stats menu.

LV	HP	AT	DF	EXP to next LV	Total EXP to LV
1	20	0	0	10	0
2	24	2	0	20	10
3	28	4	0	40	30
4	32	6	0	50	70
5	36	8	1	80	120
6	40	10	1	100	200
7	44	12	1	200	300
8	48	14	1	300	500
9	52	16	2	400	800
10	56	18	2	500	1200
11	60	20	2	800	1700
12	64	22	2	1000	2500
13	68	24	3	1500	3500
14	72	26	3	2000	5000
15	76	28	3	3000	7000
16	80	30	3	5000	10000
17	84	32	4	10000	15000
18	88	34	4	25000	25000
19	92	36	4	49999	50000
20	99	38	4	N/A	99999

Trivia

• When the protagonist enters a battle with an LV of 20, their AT and DF is automatically set to 30 (equivalent to 20 on the stats screen) and their maximum HP to 99. Other than maximum HP, these changes are never seen in-game because the only instance of the protagonist's LV getting to 20 is after their battle with Sans, who is the final opponent the protagonist can practically fight.
• A "Kills" counter appears next to the GOLD stat after killing 21 monsters.