Abstract
Problem: How granular should an action point system be, and how do you decide the size of your AP pool?
Approach: Tim Cain draws on his experience designing Fallout, Arcanum, and Temple of Elemental Evil — each with different AP implementations — to analyze the tradeoffs of small vs. large action point pools.
Findings: The core question isn't granularity but pool size. Small pools (5–10 AP) are easier to learn, make choices feel weighty, and keep turns fast — but offer little room for fine-tuning and make bonuses/penalties disproportionately impactful. Large pools (100+) allow nuanced balancing and lots of player choices — but slow down turns, create leftover unusable points, and dilute the significance of individual bonuses. The best approach is to prototype iteratively: start small, then scale up only if your design demands it.
Key insight: Start with a 10-point action pool and prototype. Let the rest of your game's systems — items, skills, bonuses, stacking rules — tell you whether you need more resolution. Move the pin and try again.
Context
This video responds to a viewer question from TactDB asking where to draw the line on AP granularity. Tim notes he's shipped games across the AP spectrum: Fallout (where agility directly becomes your AP), Arcanum (which had both real-time and AP-based combat), and Temple of Elemental Evil (a turn-based game with a unified action/move bar rather than discrete action points). The question of AP "resolution" — base 100 with modifiers, classic D&D-style, or Fallout's attribute-derived range — is really a question about pool size.
Small Action Point Pools (5–10)
Advantages
Easier to grasp. When you can only do a couple of things per turn, the decision space is immediately comprehensible. Players don't face decision paralysis.
Choices feel meaningful. With only two actions available, it's obvious what went right or wrong. If a turn goes badly, the player can reason about which of their two choices was the mistake — they don't have to audit ten sequential decisions to find the error.
Faster turns. Critical for multiplayer games or games where enemies take individual turns. A character that can move, attack, or cast one spell resolves much faster than one that can move, jump, open inventory, drink a potion, cast a spell, take cover, and apply a bandage.
Disadvantages
Little room for fine-tuning. With a pool of 5 or 10, every single point matters enormously. Getting +1 AP is amazing; losing 1 AP is devastating. This constrains your entire design.
Bonuses and penalties have outsized impact. A +1 or +2 bonus to your pool (or a -1/-2 cost modifier) is a massive swing when you only have 4–5 points. You must carefully limit bonus frequency, control where they apply, and manage stacking rules with extreme precision. Small penalties can stack to make actions literally impossible.
Everything must be reviewed. Every action cost, every bonus, every penalty, and every stacking rule in the entire game needs to be examined with a fine-tooth comb because there's almost no wiggle room.
Large Action Point Pools (20–100+)
Advantages
Pure feels. Some players just like big numbers. 50 out of 100 "feels" different from 5 out of 10 even though they're mathematically identical. Tim calls this the "paradox of big number thinking."
Lots of wiggle room for fine-tuning. You can make walking, running, and jumping each cost slightly different amounts without any single one feeling cripplingly expensive. A dagger might allow three strikes while a slow polearm only allows one — this kind of nuanced weapon differentiation requires a big pool.
Rich bonus ecosystems. Bonuses can come from attributes, abilities, worn items, and wielded weapons. They can stack with complex rules. Players get more meaningful choices about loadouts and spell selection.
Supports interrupts and saving AP. With 100 points, saving 10–20 for a possible interrupt or block feels like a reasonable tactical choice rather than a crippling sacrifice.
Disadvantages
Harder to learn. More choices means more complexity. You can stagger complexity (fewer options early, more later), but the ceiling is inherently higher.
Slower turns. More available actions means players sit longer deciding. Enemy turns also take longer simply because enemies do more things, even without extra "thinking" time.
Leftover unusable points. When actions cost 15, 17, or 18 points, players frequently end turns with 2–3 points they can't spend on anything. Some players find this deeply frustrating. Tim emphasizes: "You can't argue player feelings away."
Bonuses feel insignificant. A +2 bonus to a 100-point pool barely registers. Tim cites the EverQuest armor example: people argued over AC 56 vs. 57 on a 0–1000 scale — a functionally meaningless difference. The same problem applies to AP: if you're choosing between a 56-cost and 57-cost action, is that really a decision?
Diluted choice significance. Things that would be major decision points in a small pool become imperceptible in a large one.
Tim's Practical Advice
Tim frames this as identical to every other design balancing decision, and offers his "stick a pin in it" method:
- Start with a 10-point action pool as your prototype baseline
- Test how your items, skills, and other systems play out within that constraint
- If you can't fit everything you need (enough bonus differentiation, player choice, weapon variety), scale up to 20, then 50, then 100
- If it doesn't work, move the pin and try again — this is why you prototype before investing in art, animations, and polish
He specifically cautions against dramatically changing pool size mid-game (e.g., starting at 10 and opening to 100 later), noting it would feel like "a very different game" and you'd lose players at the transition.
The Audience Tradeoff
Tim closes with the perennial designer tension: too simple and you bore hardcore RPG players; too complicated and you lose casual players who "just want to have fun" and don't want to evaluate dozens of actions every turn. Your design goals — which you should have written down — must guide the decision.