Systems Design In Development

ProjectTera

A 5-player co-op survival horror FPS where cooperation is the mechanic, not just the theme.

RoleSole game designer DNACall of Duty Zombies + Destiny 2 raids PlayersUp to 5, co-op PerspectiveFirst person

The Design Problem

Most co-op games call themselves cooperative but don't actually require it. You can ignore your teammates and still win. The mechanic and the theme are disconnected.

ProjectTera is built around a single constraint: cooperation has to be the game's actual mechanic, not just its setting. The world punishes division at the system level. It rewards unity with tangible power. Selfish play feeds an enemy force. Unified play builds a counter-force.

The design question I started with: what does a game look like where cooperation isn't a feature — it's the world's answer to the threat?

The Core Duality

The entire game's systems run on a single axis: The Triforce vs The Loom. Every mechanic maps to one side of it.

Triforce

Cooperation

An infinitely powerful good-aligned energy. Cannot be manufactured or controlled — only accessed through genuine unity. It cannot be cheated, purchased, or faked.

Global voice comms unlock when power is restored
Random perks, damage multipliers, weapon upgrades for the team
Tier 7 unlocks the Resilience checkpoint — earned through cooperation only
Wonder weapons advance Triforce tier when equipped on the right role

The Loom

Division

An ancient evil energy cultivated from violence, fear, and division. Every war, every manufactured conflict has been feeding it. Selfishness is its fuel.

Horde enemies hunt isolated players instinctively
Point hoarding triggers escalating debuffs and environmental punishment
The Captain dismantles everything the team built — comms, perks, objectives
Proximity voice only at map start — silence and separation are the default

The mechanic IS the message. The game's world has been designed so that every system reinforces the same truth: division has a cost, and cooperation has a power that cannot be replicated any other way.

The Core Loop — Five Phases

PHASE 01

Survival & Setup

Players split — proximity voice only. Defend barriers, earn points, open doors. The early game is a tower defense. The Loom is at full strength. Silence is the default state.

PHASE 02

Activation

Power restored. Global comms open. Gates unlock, perks become available, the environment transforms. This transition must be a moment. Audio. Visual cue. Weight. Players remember the first time their comms came on.

PHASE 03

Investigation

Main Scenario Quest goes live. Clues and breadcrumbs guide the team without stating anything directly. The world rewards attention, curiosity, and communication — never a tutorial prompt.

PHASE 04

Escalation

Weapons upgraded. Perks stacked. Side quests completed. Cooperative roles crystallize organically. Selfish play at this stage feeds the Loom and punishes the team.

PHASE 05

Encounter

The boss fight. Mechanics learned. Roles assigned. Communication and execution under pressure. Failing sends the team back — unless the Resilience checkpoint was earned.

Five Archetypes — Surrender Arcs as Mechanics

Classes were not designed and fitted to characters. The characters were discovered and the classesed themselves. Each character's story arc — what they have to give up — is expressed through what their abilities actually do in play.

Tank // STR-CON

The Russian Operative

The Wall

Surrenders nationalism and judgment by absorbing damage meant for people he once considered beneath him. Every hit he takes for the Chinese Soldier or the Agarthan is his arc made playable.

Healer

The Agarthan

The Lifeline

Surrenders certainty by keeping alive the very people who shattered their worldview. Every heal is an act of chosen humility. Ancient knowledge expressed through sustaining others.

INT-Caster // Force Multiplier

The German

The Force Multiplier

Surrenders occult power wielded for supremacy. His buffs strengthen the Russian, the Chinese Soldier, the Agarthan — people his ideology marked as lesser. Every cast is his arc in a single action.

DEX // Executioner

The CIA Operative

The Scalpel

Surrenders American exceptionalism. His precision means nothing without the Russian absorbing damage, the Agarthan keeping him alive, the German amplifying his output. He cannot be exceptional alone.

STR // Sustained Damage

The Chinese Soldier

The Hammer

Surrenders collective duty over national purpose. His abilities scale directly with team cooperation level. The more unified the team, the more powerful he becomes. Cannot reach his ceiling alone.

Wonder Weapon Deep Dive

Wonder weapons in ProjectTera are gameplay philosophies in item form — not class-locked, but the community will enforce correct assignment organically because equipping on the intended role advances the Triforce tier.

Legendary // Universal

Combinator SR-11

The most cooperative wonder weapon ever designed for this genre. Every conversion serves a different role and phase. The misfire creates a skill ceiling. The sacrifice creates genuine selflessness built into the weapon mechanic.

Base State

Misfire. Unstable without a loaded powerup — fires empty and triggers an unpredictable spatial teleport. A liability for new players, a strategic escape tool for experienced ones. A weakness that becomes skill expression at high levels.

Max Ammo

Infinite ammo with elemental effect selection. A brief choice window on load — fire, thunder, cryo, and others. Skilled players decide instantly. New players panic or miss the window. Same mechanic, two skill floors.

Insta Kill

Chain lightning horde clear — a direct nod to the Wunderwaffe DG-2, evolved. Heat mechanic: fire too fast and it damages the wielder. Push further and it eats a perk. Power with a price.

Nuke

Fires a gravitational black hole. Pulls mob inward, damages enemies within range for ~3-4 seconds. Mob control, not elimination. Creates cooperative execution windows — the team converges to deal damage while the horde is clustered.

Carpenter

Break specialist conversion. Dramatically increases weak point and stagger damage. Required to trigger boss damage phases. The Combinator user isn't doing the most damage — they're enabling everyone else to do more.

Full Power

Temporal restoration. Shoot destroyed objectives to restore them against a timer. The direct counter to The Captain — everything it dismantled, Full Power Combinator takes back. Teammates pop speed buffs and run memorized routes.

Mini Perk

Sacrifice. The wielder gives up their chamber slot permanently. The entire team gains one additional random perk. The player who makes this call isn't making themselves stronger — they're making everyone else stronger. No scoreboard tracks it. The moment itself is the reward.

The Combinator SR-11 is the Triforce philosophy made playable. The misfire punishes selfishness. The sacrifice slot rewards putting the team above yourself. Every conversion serves a different phase and role. This is what a wonder weapon looks like when the design brief is cooperation.

Enemy Design — Every Enemy Asks a Question

Each enemy tier is a cooperation test in physical form. The design brief: every spawn should force the team to answer the same question — are you together, or divided?

The Drone

Base Horde // Infinite

Reanimated soldiers corrupted by Loom energy. Individually manageable. Lethal the moment a player is isolated. Hunts isolated players instinctively.

Stay together. Division is not just punished by the world — it is hunted by it. The Drone is the Loom made physical.

The Thrasher

Mid Tier // Rare

Detects isolated players — sprints, debuffs movement. In groups: cowers, loses buffs. Killed inside Triforce aura: drops Max Ammo and advances Triforce tier.

Group up. The Thrasher makes cooperation mechanically profitable, not just safer. Every spawn is a free Triforce tier if you're already together.

The Captain

Elite // Rare

Dismantles everything the team built. Breaks perk machines, disables power and comms, destroys Mystery Boxes. Vulnerable to stuns and interrupts.

Focus, coordinate, interrupt. The stun window is the team's moment. The Captain is the Loom's direct answer to the Triforce — cooperation built everything it destroys.

The Flingers

Challenge Round

Airborne. Projectile-based. Interdimensional Lovecraftian horrors the Drakonians do not control. Force vertical threat tracking simultaneously with ground-level horde management.

Divide attention vertically. Someone calls the sky. Someone manages the ground. The Agarthan's callout recontextualizes the entire faction war in one line.

Encounter Teardowns — Design Primitives

I played Der Riese and Ascension firsthand and converted the reactions into authorable rules. The goal isn't what was fun — it's what rule made it fun, and how to author that rule intentionally.

Primitive 01 — Convergence Event with Opportunity Cost

Source: The Gersh Device step in Ascension. Players charge the device and fire their best weapons INTO it rather than at the horde.

A focus-fire target that triggers an event, where committing to it diverts the team from suppressing an active threat. Four stacked effects: expectation subversion, mastery recontextualized, forced convergence, and risk through diverted attention. Cooperation that is simultaneously a vulnerability.

Tera application: Boss damage phases are gated this way. The team converges to open the window while the horde pressure they were managing comes back on them. The cost is what makes the cooperation feel earned.

Primitive 02 — Synchronized Input Under Pressure

Source: The monkey buttons and computer terminals in Ascension. Multiple players must press simultaneously. Confirmed genuine forced co-op — cannot be brute-forced solo.

Simultaneous multi-player action is only meaningful when executed while the encounter is actively threatening the team. A sync gate in a calm room is a formality. A sync gate through chaos is a skill test. Pressure is what converts coordination from a Discord countdown into a mechanic.

Tera application: At five players every participant is load-bearing, so sync gates stay a skill test. Always layer the sync requirement over active threat. The Captain disabling comms mid-sync is exactly the kind of pressure that makes it land.

Primitive 03 — Recoverable Failure with a Discoverable Path

Source: The Lunar Lander step in Ascension. Calling landers in the wrong order stranded the team with no reset. The failure wasn't the mistake — it was the absence of a way back.

An MSQ step may have a failure state that costs the team and forces a retry within the same run — this raises the stakes. But every bad state must have a recovery path discoverable through observation and logic. Punishing a mistake is fair. Stranding the player with no learnable way out is not.

Tera application: This is the origin of the failure model split. Boss encounters get fast restarts. MSQ steps get recoverable failure within the run. The punishment scales with what kind of content you're failing.

Failure Model

Boss Encounters

Fast Restart

Wipe, re-pull at the encounter. No runback. An execution test where tight retries preserve flow. Governed by the Resilience checkpoint — earned through cooperation, not purchased.

MSQ Steps

Recoverable Failure

A wrong move can cost the team and force a retry in the same session, raising the stakes of the puzzle — provided the recovery path is always discoverable. A puzzle can carry consequences a boss retry cannot.

Rejected Anti-Pattern

Timing Window Difficulty

Tera's difficulty comes from comprehension and coordination, never from pixel-perfect execution windows that read as arbitrary. Named after the Lunar Lander anti-pattern. Do not build it.

Design Pillars

Non-negotiable. Every design decision is measured against these five. If a feature doesn't serve at least one pillar, it doesn't belong in the game.

01CooperationThe mechanic and the meaning are inseparable. Cooperation is not a feature — it is the world's answer to the Loom.

02Wonder and RevelationEvery secret should make the world feel more real, not less.

03Mastery Through PerseveranceThe game should never feel impossible — but should always feel just barely possible.

04Power Should Feel Earned, Never GivenEvery upgrade, weapon, and perk means something because the player survived to get it.

05Lovecraftian TempleThe environment should feel ancient, deliberate, and deeply hostile to human existence.

"Players should feel what cooperation makes possible: a team that holds together against an otherworldly threat and wins, in a world grounded enough to make that victory mean something."

— Design Mission Statement, ProjectTera GDD