Build-Up

Build-up is a mechanic that causes bullets to accumulate a status effect over multiple hits.

Whenever a hero fires at an enemy, items and abilities with Build-up add a percentage to a meter on that target. Once the meter reaches 100%, the associated status effect is triggered. The progress of a build-up is shown as round icons above the target. Build-up per shot is reduced by damage falloff, dropping to as low as 10% of its base value at maximum range.

Build-up is a related but distinct mechanic from Stacks. Unlike stacks, which are discrete increments that scale an ongoing effect, build-up functions as a percentage meter that triggers a single status effect upon reaching 100%.

Items

Items with Build-up apply their percentage to the target through bullet hits. The build-up meter decays if the enemy does not receive any new stacks for 2 seconds, at a rate of 20% per second. Melee attacks count as 1 shot for build-up purposes. Each item's build-up per shot varies by hero, as it is affected by the hero's weapon fire rate and clip size; the exact percentages can be found on each item's page.

List of items that use Build-up

Name	Effect on Trigger
Slowing Bullets	Movement Slow
Weighted Shots	Movement Slow
Silencer	Silence
Inhibitor	Damage Reduction and Healing Reduction
Toxic Bullets	Bleed
Spiritual Overflow*	Spirit Overflow

* Spiritual Overflow is a special case: its build-up affects the shooter rather than the target. However, the build-up meter still accumulates on the target being shot, meaning it is impossible to accelerate the process by shooting multiple different targets at once. It is also the only build-up source where the progress is not shown above the target.

Heroes

Some heroes have abilities that use the Build-up mechanic, accumulating a percentage on the target until the associated effect triggers.

• Infernus — Afterburn: triggers a Burn (damage over time) effect. Light Melee attacks count as 1 stack; Heavy Melee attacks count as 2 stacks.
• Mina — Love Bites: triggers a Spirit damage proc. Melee attacks do not contribute to build-up.
• Silver — Slam Fire (Tier 3): deals bonus damage if all 3 shots hit the same target.

Note: Graves' Essence Theft appears visually as a Build-Up, but it's actually a stacking effect, as the effect is applied over time.

Counters

Several items can mitigate or counter build-up effects:

• Items providing debuff resist reduce the lingering duration of build-up as well as making already thiggered effect disappear quicker.
  • Debuff Reducer and its upgrades Spellbreaker and Unstoppable
  • Blood Tribute
  • Weighted Shots
• Plated Armor provides a chance to block bullet effects from incoming shots entirely, which includes any build-up effects.
• Juggernaut slows fire rate of nearby attackers, making it harder for enemies to stack build-up quickly.

It is worth noting that Metal Skin, despite providing immunity to bullet damage, does not protect against build-up in any way; shots negated by Metal Skin still contribute their full build-up percentage.