Negative Mobility Fix V2 2026 – Mobility and Detection Fix

Fixes the negative Mobility bug, where stacking too many slows or Mobility penalties can push
a unit below 0 Mobility and cause the game to give it an extremely large move range instead. (Integer Overflow)

With this mod, Mobility cannot drop below 0. Slows still work, but they will never turn a unit
into a speed demon.

Applies to all units, including soldiers, enemies, civilians, summoned units, and units from
other mods.

Builds on RustyDios’ lightweight Event Listener approach, but closes the gaps that let some
edge cases with a ton of mods break movement.

What was missing before:

• It only re-checked Mobility when a unit was hit or first entered the mission, so penalties
  that built up at turn start or over time were missed.
• It set Mobility straight to 0, which the game could undo the next time it recalculated the
  unit’s stats, so the fix didn’t always hold.

What this version adds:

• Holds the Mobility floor in a different way, so a stat recalculation can’t wipe it out.
• Re-checks Mobility at turn start, when a unit is hit, and when damage-over-time effects
  apply.
• Covers the stacked-penalty cases that slipped through before: poison, acid, Red Fog, gas,
  flashbangs, bitter chill, ballistic shields, and similar heavy items.

• Optional settings are available in XComNegativeMobilityFix.ini.
• Requires the X2 WOTC Community Highlander.
• Not compatible with vanilla XCOM 2.
• Not compatible with the Original Negative Mobility Fix. DO NOT USE BOTH

• Kiruka for the original Negative Mobility Fix. https://steamcommunity.com/sharedfiles/filedetails/?id=2806444314
• RustyDios for the Event Listener rework this version is based on.
• Musashi and the LWOTC team for the mobility floor technique adapted from the Unstoppable_LW ability.

UPDATE:

A proper tune-up for Negative Mobility Fix. The mod still prevents broken negative Mobility values, but the fix is now smarter, lighter, and able to watch more than just Mobility.

Reworked

• Better timing. The fix now reacts when effects are applied to a unit, instead of only checking when a unit is hit or enters the mission.
• Final-value correction. Stats are corrected after other modifiers have been applied, so later recalculations are much less likely to undo the fix.
• Less overhead. Redundant checks were trimmed to keep performance smooth.

  New

  • Detection safety check. Stacked stealth or detection penalties could push detection values past safe limits and create broken negative detection ranges. This is now clamped at a safe boundary using the game’s own detection math. It only applies when the value is already broken and should not affect normal play.
  • Optional stat caps. The .ini now includes optional caps for Hacking, Sight range, and Hearing range. These are off by default and labeled for users who want to experiment.
  Thanks

  Thanks to Senior XCOM Engineer Zelfana for the event-system deep dive, the priority fix, and helping keep the implementation honest.