Arcanum 2 System Extensions

tim-cain arcanum game-design rpg-systems sequel-design troika

Abstract

Problem: How do you design RPG system extensions for a sequel when players are expected to bring over high-level characters from the first game?

Approach: Tim Cain shares his original design documents from Troika's Arcanum 2 (subtitled "Journey to the Center of Arcanum"), detailing skill specializations, Grand Master training, lost Age of Legends spells, post-doctorate schematics, expanded backgrounds, and follower behavior systems.

Findings: The extensions added roughly 80+ new skill specialization options, 100+ spell improvement points, 70+ schematic improvement points, and a restructured background system — all designed to stack on top of existing max-level characters without invalidating them.

Key insight: When designing a sequel that supports character import, extend the top of every progression tree rather than reshuffling the base — specializations, Grand Master tiers, and lost/legendary abilities give veterans new growth while keeping old builds valid.

Source: https://www.youtube.com/watch?v=IPEe0s6fjdw

1. Context

Tim Cain found a design folder from Troika literally called "Arcanum 2 System Extensions." He notes upfront that Activision Blizzard owns the rights to Arcanum, so none of this was ever implemented — but he wanted to share his design intentions both for fans and for developers working on their own sequels.

Arcanum 2 was planned as "Journey to the Center of Arcanum." The core design constraint: players should be able to keep playing the same character from the first game, meaning most extensions had to occur at the top of existing skill, spell, and schematic trees.

2. Skill Specializations

The most extensive additions were skill specializations — a new system independent of the existing Beginner/Expert/Master training tiers. Once a player achieved Mastery in a skill, they could spend one character point to buy a specialization. Each skill had 4–6 specializations, many with attribute or cross-skill prerequisites.

2.1. Bow (4 Specializations)

  • Double Damage (requires STR 12): Every arrow does double damage
  • Seeker (requires DEX 20): Arrows can curve around one corner to hit targets not in line of sight
  • Marksman (requires DEX 20): Increased critical hit chance on all ranged shots
  • Recover Arrows (requires Repair 2): Chance that fired arrows appear in the killed creature's inventory

2.2. Dodge (5 Specializations)

  • Taunt: Nearby enemies are compelled to attack you (aggro pull)
  • Evade: Increases the chance attackers switch to a different target
  • These two could synergize — a dodge specialist could either draw all aggro or redirect it, making for interesting tactical play

2.3. Melee (6 Specializations)

Included dual wield, knockbacks (like the spell effect), and stuns — all triggered automatically on a successful hit.

2.4. Thieving Skills

  • Backstab — Ninja Backstab: The target gets no chance to report the attack. Kill someone with a backstab and no one knows
  • Pickpocket: Reduced penalties for stealing wielded weapons or worn armor — literally steal a sword from someone's hand or the armor off their back
  • Prowling — Camouflage: Standing in foliage tiles makes you fully invisible (not just hard to detect) unless you attack or make sound
  • Prowling — Shadow Step: Instant short-range teleport while prowling
  • Prowling — Human Fly: Click on any building wall or facade (like the crashed blimp) and instantly reappear at any tile along that structure's perimeter

2.5. Spot Traps

  • Walk over detected traps without triggering them
  • Detecting one trap reveals all traps on screen

2.6. Tech Skills — Reverse Engineering

The standout tech specialization: with INT 20 and at least one degree in every tech discipline, you could learn any schematic just by finding an example of that item in the world. Find a mysterious gadget? Boom — you can now reconstruct it.

2.7. Total Impact

With 5–6 specializations across all 16 skills, this alone added roughly 80 new character points worth of options.

3. Grand Master Training

A new training tier above Master. Grand Master required a character point, Master training, money, and completing a quest — no shortcuts.

3.1. Examples

  • Backstab Grand Master: All backstabs become automatic critical successes
  • Repair Grand Master: Repaired items never lose maximum HP — immunity to durability degradation
  • Firearms Grand Master: Dual-wield guns

This added 16 new progression points (one per skill).

4. Lost Spells from the Age of Legends

Every magic College gained a level 6 spell — "lost spells" from Arcanum's lore. Since magic waxed and waned in the setting, spells above level 5 had been lost to history. In Journey to the Center of Arcanum, players would discover these ancient spells through quests (finding tablets, speaking with the dead, etc.).

4.1. Examples

  • Conveyance — Evacuate: Teleports you and your entire party to a predefined safe location
  • Force — Full Spectrum Aura: Replicates what Kerghan (the final boss) could do — a shimmering shield of total invulnerability where nothing can pass in or out
  • Mental — Mass Domination: Every NPC on screen (and within range off-screen) must save vs. magic or become your temporary ally. When it wears off, they have no memory of what happened

4.2. Spell Improvement System

Any spell could be further improved by spending additional points — making it deal more damage, last longer, or have a larger area of effect. Improvements had to be purchased in order (improve spell 1 and 2 before you could improve spell 3). This created over 100 new points to spend on spells alone.

5. Post-Doctorate Schematics

Tech disciplines each gained a level 8 schematic (the "post-doctorate").

5.1. Examples

  • Chemistry — Napalm: Creates a fire area where enemies who pass through it stay on fire afterward
  • Electrical — Electro Cannon: Converts ranged weapons into powerful electrical variants
  • Smithy — Adamantine Plate: Top-tier armor
  • Explosives — Shrapnel Mines: Advanced mines

Like spells, earlier schematics could also be improved — make a Molotov cocktail that does more damage, or produce more items from the same ingredients. This added over 70 new points to spend on tech.

6. Background System Overhaul

Tim divided all backgrounds into three categories:

  • Genetic: Things you're born with (e.g., "Offspring of a Troll")
  • Childhood: Things that happened in your pre-teen years (e.g., "Raised by Monks")
  • Adult: Things from your teen/early adult years (e.g., "Military Training")

In the original game, you picked one background. In Arcanum 2, you could optionally pick one from each category — so you could be born under a sign, raised by monks, and have sold your soul. Old characters with one background remained valid; new characters could stack up to three.

7. Follower Improvements

Tim also planned significant follower behavior changes:

  • Adjustable combat modes via dialogue: attack-only, heal-only, or mixed
  • Formations (a feature that was eventually implemented in Troika's later game, Temple of Elemental Evil)
  • More granular control over party member behavior to match player intent

8. Design Lesson

Tim frames the entire exercise as a design lesson for sequel developers: when your sequel supports character import from a high-level first game, extend the tops of all progression trees rather than rebuilding from scratch. Specializations, Grand Master tiers, lost/legendary abilities, and expanded character creation options all give veterans meaningful new growth without invalidating their existing builds.

9. References