There are three classes of colonists in OP2:

• Kids: All colonists start out as Children born at the Nursery. Their sole function is to grow up into Workers when trained by an active University.
• Workers: Workers are required for operation of most structures, and can be trained into up to 10 Scientists at a time at any active University.
• Scientists: Scientists are also required to operate certain structures, and can also do Research at any active Labs. They can also be assigned as Workers when there's a colonist shortage (though with a corresponding Morale hit as seen below).

Morale is a “colony happiness” value that is computed from various colony conditions, as well as events that occur during gameplay. This value ranges from 0-99, but this range is segmented into various morale levels which apply various modifiers to other mechanics in the game:

Numerous constants governing morale calculations are defined in morale.txt. For example, the morale levels and associated modifiers are defined at the top of morale.txt as M_PTS_TOT, M_RSCH_BONUS, M_FACT_BONUS, M_FOOD_BONUS, M_FERT_RATE and M_DIE_RATE respectively. The game also implements a power modifier (M_POW_BONUS) that can give a bonus or penalty to power production, but this is set to 0 for all morale levels. (The table in morale.txt also defines M_DEFECT_RATE which is 0 for all levels except Poor (5) and Terrible (10), but appears to be unused by the game).

In “morale steady” games this is typically forced to Good, but the mission designer can force morale to any of these levels.

• Despite there being a “demand %” shown for Med Centers, having excess Medical Center capacity strictly lowers the death rate (at the cost of Scientists and power to run the medical centers). While maintaining < 100% Med Center demand is necessary to avoid a morale hit by itself, further reducing demand % can have enormous benefits even in Morale Steady games.
  • Veteran OP2 players strive for 30-40% demand to give a decent reduction to death rate.
• There is limited value in having more than 1 Nursery and University:
  • Multiple nurseries do not increase birth rate, only decreasing kid death rate by providing 40 capacity for kids, but this is quickly obsoleted when Med Centers become available as they have a base capacity of 50, upgradeable to 75 (and apply to all colonists).
  • Multiple universities do not increase worker training rate (though later in the game, multiple universities can be built in order to train more than 10 scientists at a time).
• Birth rate and death rate are affected favorably by high morale, so it's in your best interest to keep morale reasonably high.
• There is no value in researching Leisure Studies / Public Performance (to build Recreation Facilities or Forums). As described below, this does not factor into Morale at all until the tech is researched, at which point it only hurts you due to the Morale penalty from not building any rec centers (which require Workers and Power to run without providing any other benefit). Since it's not a prerequisite for any other techs besides Multitainment Console Upgrade (which increases the capacity of rec centers) there is zero useful reason to research it.
• When playing as Eden, spamming Impulse Items from Consumer Goods Factories is one of the most effective ways to artificially boost morale in the late game by keeping event morale high (so long as you can spare the resources):
  • Despite Wares and Luxury Wares giving a larger morale bonus, Impulse Items are more time- and cost-effective due to having a build time of 800 and only requiring 150 common metal.
• Destroying “good” enemy buildings such as morale-related buildings has a severe negative morale effect (and in most cases you only need to destroy the enemy Command Center to win e.g. in a Last One Standing game), so unless you are at the end of the game there is little value in attacking them.

There are two kinds of morale, Base Conditions, and Events. These are handled separately. Every 256 ticks, these values are computed and used to determine a player's overall morale. This calculation is only performed for human players. For AI players, the morale level is forced to Fair.

Base conditions are derived from colony conditions such as unemployed workers, disabled buildings, food production, etc. Events are temporary morale adjustments that happen which are computed into a single value that decays over time such as kid births, disasters, structures destroyed, etc.

While many of the values in morale.txt are stored as a percentage out of 100, internally the game scales these values to be a fraction out of 256. The calculations described below use the game's scaled value as such, e.g.:

Internal Value = ((Percent * 256) + 50) / 100

The game also stores various ratios described below in terms of hundredths of a percent (i.e. 100% = 10000) to avoid floating point rounding errors in calculation. These get scaled accordingly when shown on the UI.

The following calculations are (roughly) shown in the order the game computes them during a morale update.

First, event morale decays according to the following formula:

Event Morale = (Event Morale * EVENT_DEC_RATE + (255 if Event Morale is negative)) / 256

Adding 255 in the case that event morale is negative ensures that it will get back to 0 given enough time. EVENT_DEC_RATE is a value from morale.txt used to adjust the decay rate.

Next, base conditions are calculated, determining how current colony conditions affect morale. This gives a base number from which to start morale calculations from. In the absence of events, this will become your current morale. This value can swing wildly if base conditions change significantly during the period between successive morale updates.

Residence Demand

First, if residence capacity is nonzero, residence demand is computed using the following formula:

Residence Demand = ((Kids + Workers + Scientists)) * 100 / Total Residence Capacity

Total residence capacity is the sum of Production_Capacity (as defined in building.txt, and can be further modified by techs) for all residences the player has (by default, Residence = 25, Advanced Residence = 50, Reinforced Residence = 40. Residence can be upgraded to 75 via the Environmental Psychology tech).

As mentioned before, this (and all ratios in this section) is essentially a percentage stored in terms of hundredths of a percent, to avoid rounding errors (in other words, 100% = 10000).

If residence capacity is 0, this gets set to 100%.

Food Supply

A food supply level is calculated based on the following logic:

• Surplus if Food Production > Food Consumption
• Starving if there is a food deficit
• Deficit (Big Supply) if (Scientists + Workers + Kids) * 15 < Food Stored otherwise Deficit

Disabled Building Ratio

This ratio is computed based on:

Disabled Building Ratio = (Num Buildings - Num Idle Buildings - Num Active Buildings) * 100 / Num Buildings

In the cases of no buildings (or all buildings idle), or all buildings disabled, the ratio gets set to 0 or 100% respectively.

Rec Center / Forum Demand

This defaults to 100% if rec center and forum capacity are both 0, otherwise:

Rec and Forum Demand = (Total Population * 100) / (Total Forum Capacity + Total Rec Center Capacity)

Operational Building Checks

The game records whether there are any active Nursery, University, and GORF (storing this as a boolean separately for each building type).

DIRT Average Damage Prevention

TODO: This part needs some more analysis to determine how the game figures out DIRT damage prevention

Unoccupied Colonists

Unless the population solely consists of Kids (in which case this value defaults to 0), unoccupied colonist percentage is determined:

Unoccupied Colonist Ratio = ((Available Workers + Available Scientists) * 100) / (Workers + Scientists)

Scientists as Workers

This is set to 0 if the player has no scientists, otherwise:

Scientists as Workers Ratio = ((Scientists As Workers * 100) / Scientists

Overcrowding Multiplier

An overcrowding multiplier is determined from residence demand, based on the CROWDED_* constants in morale.txt. Note that these stack as follows:

Food Modifier

This also comes from morale.txt (FOOD_*) and is based on the food supply level computed earlier, stacking as follows:

Disabled Building Modifier

Based on DIS_BLD_* in morale.txt, this corresponds to the disabled building ratio, stacking as follows:

Rec/Forum Demand Modifier

This stacks similarly to the previous modifiers, defined as 1 in morale.txt (via REC_UT_* and FORUM_UT_*):

As stated previously, this modifier does not apply if the corresponding tech is not researched (thus there is no point in researching these techs or building these).

Med Center Demand Modifier

These stack and come from MED_UT_* in morale.txt.

Operational Modifiers

These are NURSERY_ON and UNIV_ON in morale.txt.

Disaster Warning Systems

This checks if the “required” tech of the quake, lightning, tornado, volcano, or meteor unit has been researched, which enables early warnings for disasters (the tech ID comes from weapons.txt).

All of these are additive (i.e. add 2 if the tech is researched, 0 otherwise)

DIRT Damage Prevention Modifiers

These are cumulative as before, based on the DIRT_* morale.txt constants.

Unoccupied Colonists Modifiers

From UNOC_* in morale.txt.

Scientists as Workers Modifiers

From PHD_WHINE_* in morale.txt.

Difficulty Scaling

TODO: Look into this more (DIFF_* in morale.txt).

As discussed above, as certain events happen in game, this will adjust the event morale accordingly:

Notes on the above:

• Which disaster modifier gets applied is based on which of the early-warning techs are researched (as described above)
• “Good” structures are morale related buildings (e.g. Nursery, Residence, Medical Center)
  • TODO: is this an exhaustive list?
• “Bad” structures are combat related buildings (e.g. Guard Post)
• TODO: Are the worker and scientist trained events per-colonist or per-training?
• The event morale is updated at the time the game processes the event, but the actual morale update is deferred until a morale processing cycle (every 256 ticks).
  • For this reason, morale changes from events stack without any limit.

The colony population is updated every 32nd processing tick (256 ticks) for each human player. AI players are forced to 4096 workers, 4096 scientists, and 256 kids.

The following discussion makes use of M_FERT_RATE and M_DIE_RATE from morale.txt. M_FERT_RATE determines the rate at which new kids are born. The values are unintuitive: a lower value means a higher birth rate. M_DIE_RATE determines the rate at which people (kids, workers, and scientists) die. As uninituitively as before, a HIGHER value means a LOWER death rate.

In addition, the “total med center capacity” below is the sum of the Production_Capacity (as defined in building.txt and upgraded by techs) of all active Medical Centers owned by the player. This defaults to 50 for the base Medical Center and 75 with Automated Diagnostic Examinations.

First, new workers are trained from kids, if there are any to train, and the player has an active University (having more than 1 university has no effect here), the worker count is increased (and kid count decreased) based on the following formula:

Trained Workers = (((min(160, Kids + Workers + Scientists) / 40) * 3 + 36) * 4) / (Remainder + Kids)

The remainder from this division is stored and used the next time the population is updated in this formula (starting at 0 when the game starts). This allows for fractional worker growth over multiple updates.

Next, the number of new kids is calculated based on the birth rate, if the player has an active Nursery (as before, having more than 1 nursery has no effect) and the total number of workers and scientists is less than the number of kid (i.e. kids are capped at 50% of total population), based on the following formula:

Kids Born = (Scientists / 4 + Workers / 2 + Remainder) / M_FERT_RATE

As before, the remainder is stored and used in the next update to allow for fractional kid growth over time. M_FERT_RATE is a value defined at the top of morale.txt for each morale level.

Kid deaths are computed next, if the number of kids is greater than 0, according to the following formula:

Kid Deaths = (Kids + Remainder) / (Nurseries * 40 + M_DIE_RATE / 2 + Total Med Center Capacity)

The remainder is stored for use in the next update, and total med center capacity is a previously computed value for each player. In other words, Nurseries are assumed to have a capacity of 40 (note that this becomes fairly pointless once Med Centers are available as they lower death rate for all colonists and have a higher capacity, for the same upkeep in workers, scientists, and power). M_DIE_RATE comes from morale.txt based on the player's current morale level.

Worker and Scientist deaths (assuming there are any) are separately computed similarly using the formula below:

Worker or Scientist Deaths = (Workers or Scientists + Remainder) / (Total Med Center Capacity + M_DIE_RATE)

As before, the remainder is stored and used in the next update (separately for scientists and workers).

Scientist training is not handled here, because that is something that is manually initiated at the University by the player.