Arcanum Experience Points

tim-cain arcanum experience-points game-design rpg-design xp-systems

Abstract

Problem: How should experience points be distributed in an RPG that supports combat, stealth, diplomacy, and companion-based playstyles?

Approach: Tim Cain recounts the internal debate at Troika Games during Arcanum's development, where he favored quest-only XP but was convinced by the team to add combat XP.

Findings: Arcanum shipped with a hybrid system — quest XP as the primary source, plus per-hit XP (proportional to damage dealt) and a killing blow bonus (20% of combat XP pool). This rewarded solo fighters most, while companion-heavy and stealth builds received less XP, mirroring how those playstyles already made the game easier.

Key insight: Tim now believes quest-completion-only XP is the best approach, as it makes the game agnostic about how players solve problems — but he emphasizes that evolving your design philosophy over time is a sign of growth, not weakness.

Source: https://www.youtube.com/watch?v=MSI3sRJ53jU

1. The Eternal XP Debate

The source of XP in RPGs has always been contentious. Tim references his earlier videos on the topic, noting that combat XP disadvantages non-combat characters, and skill-use XP introduces a cascade of exploitable problems. His settled position today: quest completion is the answer.

2. The Team's Arguments for Combat XP

During Arcanum's development, Tim wanted quests to be the sole major source of XP, reputation, and items. But the team pushed back with several arguments:

  • Build accessibility — Some builds (low intelligence, bad reputation) couldn't access most side quests. Only main story quests were guaranteed for everyone.
  • Unavoidable combat — Random wilderness encounters and certain dungeon layouts forced fights regardless of build. Sneaking past wasn't always possible.
  • Companions as a workaround — Players could already avoid personal combat by letting companions fight, so combat XP wouldn't break anything new.
  • Grinding needs — Players wanted a way to gain XP after exhausting all side quests but before finishing the main story. Without combat XP, there'd be no advancement source left.

3. The Compromise: Hit-Based + Killing Blow XP

Tim agreed to add two combat XP sources alongside quest XP:

  • Per-hit XP — Awarded every time the player scores a hit, proportional to damage dealt.
  • Killing blow bonus — Roughly 20% of the total combat XP pool went to whoever landed the final hit.

3.1. Consequences by Playstyle

This created a clear hierarchy: a solo pure fighter leveled fastest (all quest XP + all combat XP), while companion-focused or stealth characters got less. The team argued this was fair — companions and stealth already made the game easier, so the solo fighter was effectively playing on hard mode and deserved faster progression.

A stealth character sneaking past an encounter and a companion-heavy character letting followers do the fighting were treated identically: both avoided personal combat, both got zero combat XP.

4. Letting the Team Shape the Game

Tim draws a parallel to the Fallout ending — not his idea, but Leonard Boyarsky's, and it made the game better. He advocates for a middle ground between design-by-committee and design-dictator: listen to the team's ideas, but ultimately one person decides. He was genuinely convinced combat XP was a good addition at the time.

He also notes this openness doesn't always work out — he considers Arcanum's "everything costs one character point" system a bad change he was talked into.

5. His Current Philosophy

If remaking Arcanum today, Tim would use quest-only XP. The advantages:

  • The game becomes agnostic about problem-solving method — sneak, talk, fight, or skip entirely, it doesn't matter as long as the quest resolves.
  • No need for grind XP sources when the game ends with the story.

6. The Meta-Lesson

Tim closes with broader advice for designers: don't lock your philosophy in stone. His views evolved over 45 years. Only closed-minded people never change their minds. The Arcanum XP system is a concrete example of believing one thing, being convinced otherwise, trying it, learning from it, and ultimately returning to the original instinct with deeper understanding.

7. References