Time Units

Time Units

Time units or TUs are one of several vital resources available to X-COM Soldiers.

A single game turn is an unspecified amount of time. There has been many arguments as to what duration of time this could be, but no one can agree on a hard figure. Here's one example of a detailed estimate. Maybe it's a minute, maybe it's 5 seconds. In any case, a game turn is merely the duration in which actions are taken by each side.

The Time Unit is a fraction of this time. If a soldier has a maximum of 64 Time Units, then each TU is worth 1/64th of a turn. A soldier with 80 TUs uses 1/80th of the turn for every TU spent. This means that Time Units are synonymous with speed.

Starting Values

New recruits always begin with a value from 50 to 60 time units.

Improvement

TU 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 TUs. At recruit minimum (50 TUs), an average of 2.2 points are earned. This slopes evenly down to where, at cap minus one (79), an average of 1.0 points are earned (range 0-2).

Maximum Caps

A soldier's TUs caps at 80, but it is possible to 'overflow' the cap by one point on the last combat when you go over the cap (in other words, 79 plus 2 gives you 81). On average, you have a 33% chance of getting capped at 81 instead of 80: this is because there are two ways to get capped at 80 (78+2 or 79+1), but only one way to reach 81 (79+2). Once at 80+, all TU improvements cease.

Older versions of X-COM did not have a cap and stats could reach 255 and then wrap back to 0. This could potentially cripple an otherwise good soldier.

- Are you sure? I've played the DOS version (1.0) for years and I don't ever recall seeing that problem. Delete this message when you read it Hobbes

- A long time ago, when the games were still on these ancient thingies known as floppy diskettes (and these being the 3 inch variants, quite new at the time), your stats weren't capped and could continue to increase until they hit the byte limit of 255 points. As your attributes were stored in a byte, when the value went beyond 255, it loses the high bit, effectively returning the value back to 0. -NKF

- I didn't saw this problem, even when I brought the best soldiers to Cydonia and the (global) highest ranking one (a Colonel) had a TU amount of over 180... Quite annoying that firing just one aimed shot from a laser rifle takes more TUs than the max TUs of the team's best squaddie... amitakartok

Time Unit Expenditure

Time Units are spent in two ways. In fixed amounts and in percentages.

Fixed Costs

Actions such as walking, turning, moving inventory around, reloading weapons, and using the medkit all cost the same fixed amount of TUs for all soldiers. Soldiers with high TUs benefit the most from fixed TU actions. Scouts benefit from high TUs the most. Dedicated medics and psi troopers can also benefit from high TUs.

Fixed cost actions include:

• Bringing up the Medi-Kit interface: 0 TUs(free)
• Turning in place: 1 TU per 45 degrees
• Kneeling: 4 TUs
• Standing after kneeling: 8 TUs
• Unloading a weapon: 8 TUs
• Changing elevation in a Flying Suit: 8 TUs
• Using a Medi-kit charge: 10 TUs
• Reloading a weapon: 15 TUs
• Using a Psi Amp: 25 TUs
• Walking: Dependent on terrain, from 4 to 18TUs per square; diagonal movement costs 50% more
• Adjusting inventory (other than unloading or reloading a weapon)

Percentage Costs

Actions that cost a percentage, such as firing a gun or priming a grenade, will always take a percentage of the soldier's base Time Units to perform. This means that the soldier's base TUs has no bearing on how many times the action can be performed during any given turn. For example, if a weapon costs 25% to fire, it can only be fired a maximum of 4 times a turn, for every soldier, regardless of his/her amount of TUs. Because of this, it's smart to put low-TU soldiers in long range fire support roles.

Note: Costs are based on the maximum amount of your soldier's TUs, not the current amount. Therefore, percentage costs do not change as you use up TUs (or if you have more TUs than usual, due to going berserk).

Note: Due to integer rounding, some TU values will allow certain weapons to be fired more than usual. For example, a solder firing a heavy plasma with auto-fire (35% TUs) will get 3 rounds at some TU values but not others.

Percentage cost actions include:

• Firing any weapon: Dependent on weapon and firing mode from 18% up to 80% Max TU
• Throwing: 25% Max TUs
• Using Motion Scanner: 25% Max TUs
• Using Stun Rod: 30% Max TUs
• Using Mind Probe: 50% Max TUs
• Priming an explosive: 50% Max TUs

Encumbrance

Encumbrance is the weighing down, or burdening, of a soldier. Any weight over the soldier's strength stat will cause encumbrance. This lowers their available TUs, essentially slowing them down.

Formula:

Encumbrance = Strength / Carried Weight*


If Encumbrance >= 1 then

   Available TUs = Base TUs

Else

   Available TUs = INT(Encumbrance x Base TUs)

Example:

A low-end Rookie with a base of 50 TUs, 20 strength, and carrying 80 weight units, will
have an encumbrance of 25%, leaving him with a meager 12 TUs per turn. 

*If Carried Weight = 0, then Carried Weight = 1

Fatal Wounds

Each fatal wound to the left or right leg reduces the soldier's TUs by 10%.

Influences

• Time Units heavily influences a unit's Reactions.
• Closely associated with TUs is the Energy stat.
  • A moving unit consumes both TUs and Stamina (Energy) points. How many energy points are consumed depends on the type of terrain the unit is walking on. More difficult terrain consumes more energy and time units. All other actions only consume TUs. The sole exception is that some aliens use Energy for turning around as well and can provoke reaction fire by just turning around while a soldier cannot.
  • Energy recovery is calculated by taking your soldier's initial time units (the TUs they had as a new recruit) and dividing this by three. Drop the fraction. This will be the soldier's energy recovery rate throughout the campaign. For more details, see Energy.

Time Unit Walking Usage Tables

Refer to the Walking Costs table.

See Also

Inventory TU Table

Reactions

Energy

Strength

Item Weight

Fatal Wounds

Recruit statistics

TU Cost table for walking