This guide is based on the mechanics in Megabonk (version 1.0.7), covering how upgrades work, the effects of rarity, and the buffs that apply to weapons and tomes. All information is structured with tables for clarity.

How Upgrades Work

Each weapon has its own list of stats that may be included in an upgrade. The included stats are chosen randomly, so different stats may appear if an upgrade is skipped. A common weapon upgrade may select one or two stats, while higher rarities always select two stats. Weapon upgrades only affect the specific weapon they are applied to.

Each tome is associated with a single stat, so upgrades include only that one stat regardless of rarity. Tomes affect the Character Stats shown in the pause menu, which influence all weapons.

Upgrades are additive. For example, a common Sword upgrade adds +2 to Damage (if included). A common Damage Tome upgrade adds +0.08x to the stat.

Some stats stack multiplicatively (e.g., a weapon's Damage is multiplied by the Damage Tome's multiplier for the final value). Others stack additively. Character Stats are modified by sources including tome upgrades, charge shrine upgrades, character initial stats, special abilities, items, and greed shrines. See the Stat Formulas section below for detailed stacking mechanics.

The Effect of Rarity

Rarity affects the size of the stat improvement via a multiplier factor. Common-rarity upgrades serve as the base, and higher rarities are calculated by multiplying the base value by the Rarity Factor.

RarityFactor
Common1x
Uncommon1.2x
Rare1.4x
Epic1.6x
Legendary2x

For example, Sword upgrades improve stats as follows (base common values multiplied by the Rarity Factor):

RarityDamageProjectile CountKnockbackSize
Common+2+1+0.5+20%
Uncommon+2.4+1.2+0.6+24%
Rare+2.8+1.4+0.7+28%
Epic+3.2+1.6+0.8+32%
Legendary+4+2+1+40%

Which Buffs Apply

Every weapon can upgrade its Damage stat. Other buffs vary by weapon. Weapons are listed alphabetically with their upgradable stats, initial values, and common upgrade amounts (scale by Rarity Factor for higher rarities).

Tomes buff specific Character Stats, which apply globally to all weapons. Initial Tome Stats are 0 except for Damage Tome (1x). Picking up a tome provides an immediate common-rarity upgrade. The Damage Tome is multiplicative; others are likely additive.

Weapon Buffs (A-E)

WeaponStatInitialUpgrade (Common)
AegisDamage10+2
Knockback3.0+0.8
Projectile Count2+1
Size100%+15%
AuraDamage6+1.4
Size100%+14%
AxeDamage6+1.5
Duration0.8s+0.08s
Projectile Count2+1
Size100%+10%
BananarangDamage9+2
Projectile Count1+1
Projectile Speed1+0.1
Size100%+14%
Black HoleDamage4+1.3
Duration2s+0.12s
Projectile Count1+1
Size100%+13%
Blood MagicDamage9+1.5
Projectile Count1+1
Size100%+15%
BoneDamage11+2.5
Knockback1.3+0.3
Projectile Bounces1+1
Projectile Count1+1
Projectile Speed0.4+0.2
BowCrit Chance0%+8%
Crit Damage0%+18%
Damage9+1.8
Projectile Count1+1
Projectile Speed1.5+0.8
Size1+0.2
ChunkersDamage12+3
Knockback2.5+0.6
Projectile Count2+1
Projectile Speed1.5+0.4
Size100%+20%
DexecutionerCrit Chance0%+5%
Damage9+2
Projectile Count1+1
Size100%+20%
DiceCrit Chance17%+10%
Crit Damage0%+20%
Damage0+2
Projectile Count1+1
Projectile Speed0.6+0.2
Size100%+15%
Dragon's BreathDamage15+3
Duration1s+0.2s
Size100%+15%

Weapon Buffs (F-Z)

WeaponStatInitialUpgrade (Common)
FirestaffDamage10+2.5
Projectile Count1+1
Projectile Speed0.5+0.1
Size100%+16%
FlamewalkerDamage5+2
Duration1.5s+0.18s
Projectile Count1+1
Size100%+15%
FrostwalkerDamage9+2
Duration1.6s+0.12s
Size100%+10%
Hero SwordDamage11+2
Projectile Count1+1
Projectile Speed30+4
Size100%+15%
KatanaCrit Chance0%+8%
Crit Damage0%+20%
Damage11+2.2
Projectile Count1+1
Size100%+20%
Lightning StaffDamage7+2
Projectile Bounces0+1
Projectile Count1+1
Size100%+20%
MinesDamage10+3
Duration4s+0.4s
Projectile Count1+1
Size100%+15%
Poison FlaskDamage1+0.5
Duration3s+1s
Projectile Count1+1
Projectile Speed12+2
Size100%+15%
RevolverCrit Chance5%+10%
Crit Damage0%+20%
Damage5+2.5
Projectile Bounces0+1
Projectile Count6+1
Projectile Speed2.0+0.4
ShotgunCrit Chance5%+7%
Damage9+3
Knockback2.5+0.4
Projectile Count1+1
Size100%+15%
Slutty RocketCrit Chance5%+8%
Damage11+2
Projectile Count1+1
Projectile Speed1+0.2
Sniper RifleDamage22+4
Projectile Count1+1
Size100%+13%
Space NoodleDamage10+2
Duration4s+0.2s
Size100%+20%
SwordDamage11+2
Knockback2+0.5
Projectile Count1+1
Size100%+20%
TornadoDamage8+2
Knockback3+0.6
Projectile Count1+1
Projectile Speed20+4
Size100%+14%
Wireless DaggerDamage9+2
Duration (rare)1.5s+0.25s
Projectile Bounces1+1
Projectile Count1+1
Projectile Speed0.8+0.1

(Note: Corrupted Sword data is incomplete in the source.)

Tome Buffs

StatCharacter InitialTomeTome InitialTome Upgrade (Common)Shrine Upgrade
Max HP100HP Tome0+25+15
HP Regen10Regen Tome0+40+20
Overheal0
Shield0Shield Tome0+25+5
Armor0%Armor Tome0%+12%+5%
Evasion1%Evasion Tome0%+10%+5%
Lifesteal0%Bloody Tome0%+10%+6%
Thorns0Thorns Tome0+15+5
Damage1xDamage Tome1x+0.08x+12%
Crit Chance1%Precision Tome0%+7%+5%
Crit Damage2x
Attack Speed100%Cooldown Tome0%+7.5%+6%
Projectile Count0Quantity Tome0+1+1
Projectile Bounces0
Size1xSize Tome0%+10%+8%
Projectile Speed1xProjectile Speed Tome0%+15%+10%
Duration1xDuration Tome0%+15%+8%
Damage to Elites1x+10%
Knockback1xKnockback Tome0%+20%+10%
Movement Speed1xAgility Tome0%+15%+8%
Extra Jumps0+1
Jump Height7+10%
Luck0%Luck Tome0%+7%+5%
Difficulty0%Cursed Tome0%+3.5%+8%
Pickup Range5Attraction Tome0%+75%+20%
XP Gain1xXP Tome0%+9%+7.5%
Gold Gain1xGolden Tome0%+12%+7.5%
Silver Gain1xSilver Tome0%+12%+7.5%
Elite Spawn Increase1x+15%
Powerup Multiplier1x+10%
Powerup Drop Chance1x+5%
Chaos Tome

Stat Formulas

This section details how stats are calculated and stack. Terminology:

  • Weapon Stat: Value in weapon upgrade menu (e.g., Sword Damage = 13).
  • Tome Stat: Value in tome upgrade menu (e.g., Damage Tome = 1.16x).
  • Shrine Stat: Sum of charge shrine upgrades from Shrine Logs.
  • Character Stat: Value in pause menu stats.
  • Effective Stat: Final combined value (e.g., actual damage dealt).

Upgrades stack additively on their stats.

Key Formulas

  • Damage: Multiplicative. Effective Damage = Weapon Damage * Character Damage. Character Damage = Initial Character Damage * Tome Damage * (1 + Shrine Damage).
  • Projectile Count: Additive. Effective Projectile Count = Weapon Projectile Count + Character Projectile Count. Character Projectile Count = Initial + Tome + Shrine.
  • Projectile Bounces: Not modified by tomes or shrines.
  • Size: Mixed. Effective Size = Weapon Size * Character Size. Character Size = Initial Character Size * (1 + Tome Size + Shrine Size).
  • Duration, Knockback, Projectile Speed: Likely multiplicative (Weapon Stat * Character Stat).
  • Crit Damage: Preliminary: Effective Crit Damage = (1 + Weapon Crit Damage) * Character Crit Damage * Effective Damage. Character Crit Damage = Initial * (1 + Shrine Crit Damage).
  • Pickup Range: Mixed. Character Pickup Range = Initial * (1 + Tome + Shrine).
  • Jump Height: Likely multiplicative.
  • Evasion: Additive with hyperbolic adjustment. Character Evasion = Internal Evasion / (1 + Internal Evasion). Internal = Initial + Tome + Shrine.
Internal EvasionCharacter Evasion
10%9%
20%17%
50%33%
100%50%
200%67%
500%83%
1000%91%
2000%95%
  • Armor: Additive with hyperbolic adjustment. Character Armor = Internal Armor / (0.75 + Internal Armor). Internal = Initial + Tome + Shrine.
Internal ArmorCharacter Armor
10%12%
20%21%
50%40%
100%57%
200%73%
500%87%
1000%93%
2000%96%