One of Fragtrap's skill trees, Fragmented Fragtrap, focuses on some Subroutines that give bonuses and penalties to different weapons.

How do Subroutines work, what are Frag Stacks, and how bad is Tripleclocked?

  • 2
    @FrankV I love them... while I play solo and have infinite time to swap weapons, plan my moves and generally adapt the pace of the game to current Sub. They force me to experience diverse things and work towards all the badass challenges. But as soon as I'm in coop, yeah, I just spec out.
    – Orc JMR
    Commented Nov 21, 2014 at 17:41

1 Answer 1


General description, see math below

Skills in Fragmented Fragtrap tree give immense bonuses to certain weapon types, while penalizing all others, incentivizing the player to switch weapons to match the current Subroutine.

Subroutines are time-based, each one being active for 100 seconds. Frag Stacks are basically units of time - you are granted 100 Frag Stacks at Subroutine activation, and they decay at a rate of one per second. Down the skill tree there are skills that allow the player to prolong or shorten a Subroutine's duration as follows:

  • Grenade Vent adds up to 5 Frag Stacks per Grenade thrown
  • Cryogenic Exhaust Manifold subtracts up to 5 Frag Stacks on a Slam
  • Float like a Bee adds up to 5 Frag Stacks on a Melee Kill

There are four skills that unlock different Subroutines, first two of which are mandatory, while other two are optional. Only one Subroutine is active at any time, and learning more skills just adds new Subroutines to the pool they are randomly picked from.

  • Gun Subroutines increase Damage, Fire Rate and Reload Speed of a single gun type, while decreasing Damage of other gun types. Grenades and Melee are not affected.
  • Defensive Subroutines increase Capacity and Regeneration of either Health or Shields, while decreasing Damage with all guns. Grenades and Melee are not affected.
  • Melee Subroutine drastically increases Melee Damage, while decreasing Damage with all guns. Grenades are not affected.
  • Elemental Subroutines increase Damage of a single element, while decreasing Damage of other elements. Grenades are affected, non-elemental guns and Melee are not.

The bonuses are pretty modest until you get Tripleclocked skill at level 14. It multiplies all bonuses and penalties of Subroutines by a varying factor of up to 3 depending on Frag Stack count - multiplier is x1 at 100 Frag Stacks and reaches x3 by Subroutine expiration.

Fortunately, negative modifiers in Borderlands are handled by an asymptotic formula of 1/(1-x) - that means that a penalty of -75% does not leave 25% of a value ("4 times less"), but 1/(1+0,75) = 57%. Considering this, here is a table of all possible bonuses or penalties of Subroutines:

                        Gun Damage  Fire Rate  Reload Speed  Wrong Gun Damage
Gun Subroutine             +25%        +20%        +20%            -13%
 Tripleclocked Max         +75%        +60%        +60%            -31%
                         Capacity  Regeneration                 Gun Damage
Defensive Subroutines      +35%      +2.5%/sec                     -13%
 Tripleclocked Max        +105%      +7.5%/sec                     -31%
                       Melee Damage                             Gun Damage
Melee Subroutine          +150%                                    -20%
 Tripleclocked Max        +450%                                    -43%
                      Element Damage                       Wrong Element Damage
Elemental Subroutines      +32%                                    -14%
 Tripleclocked Max         +96%                                    -32%

Note: Tripleclocked Health and Shields always receive +105% Capacity, only Regeneration ramps up with Frag Stacks.

Oh, and one more bit of math:

                        Gun DPS   Wrong Gun DPS
Gun Subroutine            +50%        -13%
 Tripleclocked Max       +180%        -31%
  • Tediore reloads are grenades, and are not affected by bonuses or penalties to bullet damage.
    – Orc JMR
    Commented Nov 20, 2014 at 15:32
  • Do they count as grenades as far as Grenade Vent is concerned?
    – Unionhawk
    Commented Nov 20, 2014 at 15:54
  • @Unionhawk Yes, totally, all grenade bonuses affect Tediore reloads.
    – Orc JMR
    Commented Nov 20, 2014 at 16:30
  • I have re-read the question and only now realized Unionhawk may have asked about if reloading a Tediore gives Frag Stacks. No, it doesnt, "reloading a Tediore" doesn't count as "throwing a grenade". But the projectile that reloading results in is considered a grenade, and gains damage bonus.
    – Orc JMR
    Commented Dec 11, 2014 at 3:35

You must log in to answer this question.

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