The game is intended to follow the core design ideas of the original X-Com: UFO Defense.
That game consisted of randomly generated tactical combat segments with an overarching strategic meta game. The combat was highly asymmetric with the sides having vastly different resources, methods and goals. The mod should provide this experience to the players, only from a different perspective.
Tactical combat: The base premise is the same as in the original game.
- Eliminate the other team to win the mission. In this case, the losing side will incur loss of Resources and/or loss of Influence and the winning side may gain Resources and Influence. Due to the asymmetric nature, it is not always possible or feasible. In this case, the players can retreat and abort.
- Retreat will mean a mission failure for the side that invoked it. Both sides can abort the mission and retreat. Upon retreat, both sides may have losses but also may have gains. Inflicting casualties, securing loot and retreating with no loss can be a viable tactic when facing though opposition.
- Base defense missions don't have retreat option for the defenders.
- Terror mission retreat will have great negative impact to the retreating side.
+ Standard guns, explosives, rockets: Cheap, accurate, available from the start. Deals moderate damage, uses regular ammo. The more ammo an operative carry, the slower he can move.
+ Laser weapons: Expensive, needs research. Easier to aim with but less accurate. Slightly higher damage output. The weapon recharges, no need for extra ammo.
+ Plasma: Very expensive, massive damage output (easily one shot kill), has to be researched.
- Weapon, equipment or alien race availability will be based on strategic decisions. If the players decide to spend on fields other than tactical gear, the operatives may not have easy access to heavier weapons.
- Operative skills. Operatives have unique HP, Stamina, Movement speed and base Accuracy values. These values can increase if the operative survives long enough. Players will always control the same operative until the demise of him/her in combat.
- Operative death. Resources will be deducted from the side to cover the replacement. Also the replacement will have basic skills again. The death of the operative is permanent.
Strategic meta: Similar to the original but simplified on some levels.
- Victory conditions: Destroy all X-Com bases. Bankrupt X-Com by infiltrating or influencing the governments to cease support for the initiative.
At the beginning of each month, the players on the Alien side can select from a set of missions and tasks by placing a High, Medium and Low priority objective. For example
"Harvest/Europe/Floater, Flights 5, Cost: 20 RP, Gain: 100 RP”
“Infiltration/Asia/Sectoid, Flights: 8, Cost 100 RP, Gain: 100 Influence”
“Abduction/N America/Muton, Flights 6, Cost: 30 RP, Gain: 50 RP, 20 Influence”
“Upgrade forces, Cost: 25 RP, Gain: 1 tech level”
Top 4 selections will be executed during the month.
- Victory condition: Destroy the base in Cydonia
-Decision making: Very similar to the Alien side. Players select from a set of options in each month using 3 different priority picks. For example:
“Build/Upgrade base in Europe, Cost: 100 RP, Gain: 10 UFO Detection Perm, 10 Anti UFO Perm”
“Research Plasma Rifle Cost: 50 RP, Gain: Plasma rifle available”
“Hotspot Patrols, Cost: 20 RP, Gain: 10 UFO Detection Temp, 10 Anti UFO point Temp”
“Upgrade air assets Cost: 40 RP, Gain: 10 Anti UFO point”
“Upgrade tactical weaponry, Cost 20 RP, Gain: 5 Operative equipment allowance ”
“Deploy Laser Rifle to the field, Cost: 40 RP, Gain: Halve laser rifle equipment cost”
Top 4 selections will be executed during the month.
Once the selections are made, the game will calculate all the Alien mission flights and the Detection and Interception chances. Bigger the UFO and Higher the detection rate in the continent the more likely the flight will be detected. The higher the Anti UFO rating the more likely that the detected UFO will be shot down. The bigger the UFO, the more likely the Anti UFO value will be decreased for the region permanently. The higher the influence of XCOM in the region, the more likely that Landed UFOs will be reported to XCOM. Terror missions and Base attack missions are always reported to XCOM.
For every downed, landed and reported mission, the game picks or generates a random map based on pre-existing maps or map tiles.
The month then commences by the players participating in the chain of tactical missions. The single missions are fought once, no redo regardless of the outcome. In case of stealthy Alien missions or low detection values, it is possible that there is no tactical mission for the month. In this case, all the alien missions are successful by default.
A campaign will run until its completion and then a new campaign starts. In both sides multiplayer, the campaign can pause until a certain number of players on the server. In XCOM Only Co-op mode, the Aliens are bots and the X-Com players fight against them. Finally it may even run in single player where the player selects a side and fights alongside and against bots. The issue here is that bot allies may be more of an annoyance than real help.