In a campaign without action points, how should the DM change the artificer?

Question

The artificer base class receives at level 1 the special ability infusions, the description of which says, in part, that

Many infusions have long casting times, often 1 minute or more. An artificer can spend 1 action point to imbue any infusion in 1 round (like a spell that takes 1 round to cast). (Eberron Campaign Setting 31)

What house rule—if any—should be made to accommodate this ability in a campaign that does not use Eberron-style action points yet that still wants to include the base class artificer?

Answer 1

Give them a scaling, daily use-limited ability to reduce their infusions' casting times

While the artificer is an incredibly strong class, their ability to use infusions rapidly through action points is not, strictly, one of their strengths. Instead, it's more of a quality-of-life thing, allowing them to actually use infusions in cases where they don't have a significant amount of time before encounters to plan and set up their abilities.

Actually giving them action points is an option, but it's one that opens up more doors, or if you don't want other action point-related abilities to be used, requires more exceptions to be written in. I am of the mind that "no action points, but you can do this new thing" will probably feel better to the player than "you can do the thing that all characters get in Eberron, but actually not really, it's just for this one ability." A slight difference, but an important one.

Thus, my suggestion is to give them this ability:

Fast Infusion: Once per day, you can imbue an infusion in 1 round, instead of its normal casting time. At character level 5th and every five character levels thereafter, you can use this ability an additional time per day.

Why this scaling? Action points follow the following progression (ECS p. 45):

\begin{array}{c|c c} \text{Character Level} & \text{Action Points} \\ \hline \text{1st} & \text{5} \\ \text{2nd—3rd} & \text{6} \\ \text{4th—5th} & \text{7} \\ \text{6th—7th} & \text{8} \\ \text{8th—9th} & \text{9} \\ \text{10th—11th} & \text{10} \\ \text{12th—13th} & \text{11} \\ \text{14th—15th} & \text{12} \\ \text{16th—17th} & \text{13} \\ \text{18th—19th} & \text{14} \\ \text{20th} & \text{15} \\ \end{array}

The standard suggested adventuring day in D&D 3.5 is composed of four encounters (DMG p. 49), and the way experience math works, it should normally take about 13–14 encounters to level up (or four days of adventuring at a solid pace). This means that you can divide the number of action points per level by 4 to figure out how many you'd use in a day if you were conservative with them. I have placed the break points on the daily uses at a level or two lower than you'd have the action points in question, because this is a more limited usage than action points would have.

This ability would also allow the artificer player to have their infusions truly work on a per-day basis, instead of tracking a "consumable" that relies on the pace of the game (that can be a problem at times, in my experience, especially with campaigns slower leveling than the base game expects by default).

This also would mean that it's entirely possible for the artificer to get more "rapid infusions" per level than they might have with action points. This has some upsides and downsides—while it might, from a technical standpoint, be extra power, it's also a step up in playability. With action points, the player must carefully try to guess how to use them, based on expectations of how fast they'll level up. This doesn't have that, and is probably going to create a less stressful gameplay experience (something the artificer is, given its complexity, in short supply of).

Alternatively, give them action points that can only be used for this class feature

... and bar them from taking other abilities or character options related to action points, such as Wand Surge, Action Surge, or unfettered heroism. This will lower the number of options they can take, and may do so in a way that feels worse to the player than the above. In my experience as a game developer, being giving someone a replacement ability generally tends to be better-received than heavily restricting an ability to make it fit, so this would not be my suggestion.

Or if you want, give everyone action points

Action points were originally printed in Unearthed Arcana, where they were quite a bit more imbalanced than Eberron's revised rules for them. They were used in the setting to help push the tone that the writers intended, but there isn't anything intrinsically tying them to Eberron, and it may be that your game is improved by the addition! It might not be, though, especially if your game has a relatively slow level-up pace, and it's possible that it'll just detract from players' enjoyment by adding one more thing to track.

Even if you do, though, I would still consider disallowing unfettered heroism though. The spell is incredibly strong, especially when used by an artificer with the proper feats or abilities. This is speaking as someone who has, in the past, used, abused, and cheesed the hell out of that spell in actual games. It's fun if the campaign can support it, but it far-too-easily spirals into "I have an infinite amount of this action point-based resource" (dragonmark uses, wand charges, fast infusions, etc).

Answer 2

There's two ways to look at this:

1. Characters do not have action points, period.

2. Characters have action points, but there is no general ways, allowed in your game, to spend them.

These two viewpoints are, in practice identical, -except- when it comes to the Artificer and other allowed Eberron content.

The former results in your question. The latter simply means that the Artificer's allowed class features work as printed, and those are the only methods by which the Artificer can spend his very rare action points.

Option 2 would be the "houserule" I'd use, if I didn't want to allow the normal expenditures for action points.

Note that in Eberron, there's a spell called Unfettered Heroism which grants temporary action points for rounds/level at Wiz 5. A level <8 Artificer would have access to this spell via scrolls and schemas, giving him a great deal of action points to work with, beyond his normal level-up amount.