Energy

Energy, or Stamina, refers to your soldier's abiity to sustain intense movement over several turns. Energy is only spent when a soldier walks (or flies, if wearing a Flying Suit). No other action uses energy (not even changing elevation, on a lift or in a flying suit). More energy and time units are spent depending on the difficulty of the terrain traversed.

Starting Values

New recruits will always begin with a value between 40 and 70.

Improvement

Energy points are awarded (at end of mission) any time you perform at least one primary action. Just one action is enough - additional ones do not cause more TU points to be awarded.

The possible points earned are dependent on your current Energy. At recruit minimum (40 Energy), an average of 4.0 points are earned. This slopes evenly down to where, at cap minus one (99), an average of 1.0 points are earned (range 0-2).

Maximum Caps

A soldier's Energy caps at 100, but it is possible to 'overflow' the cap by one point on the last combat when you go over the cap. On average, you have a 33% chance of getting capped at 101 instead of 100. Once at 100+, all Energy/Stamina improvements cease.

Usage

For X-COM soldiers, Energy Units (EUs) are used at half the rate of TUs. The actual formula relies on unitref.dat offset [45]:

Formula:

Energy Used = INT( TUs_Used / 2unitref[45])

Example:

All X-COM units have a unitref[45]=1. 
Crossing a standard tile to an adjacent one uses 4 TUs.
This means that they will use INT(4 / 21) = 2 EUs.

Aliens can have different values for unitref[45]. Many appear to have 0, which means they use a 1:1 ratio of Energy to TUs. Such aliens even need 1 EU to turn one facing (a 1 TU action), unlike XCOM soldiers. A few have been seen to have values of 2 or higher. With a value of 2, they don't use energy when walking to adjacent tiles, only diagonally. Values of 3+ result in little or no Energy usage; 4+ (2⁴=16) will make even the most TU-expensive tiles (12 TUs) cost 0 energy.

Fatal Wounds

Each fatal wound to the body reduces the soldier's energy by 10%.

Recovery

A soldier's ability to recover energy is determined by the soldier's Initial Time Units. Thus, their raw recruit TU value dictates this throughout their career. You can see initial TUs on the Soldier tab (Strategic view) as the darker part of the TU bar.

Formula:

Energy Recovery = INT(Initial TUs/3)

Example:

If a soldier starts with an initial value of 60 TUs, they will recover 20 EUs per turn.

Energy Recovery Chart

Time Units	Energy Recovery
50	16
51 → 53	17
54 → 56	18
57 → 59	19
60	20

Energy can also be recovered by way of stimulants from a Medi-Kit.

See Also

Time Units

Medi-Kit