Mo uses, mo problems
I love multi-use cards, and as a result, they're a part of almost every design I've crafted. The exceptions being Druids, Rail Contango, and currently Dungeon Time, Fun! I love them. I am by no means an authority on multi-use cards, or anything really, but I've experimented so much with multi-use cards that I feel confident writing about them. So, here we are. My little TED-talk on multi-use cards. I'm pretty sure this one won't be going viral!
To focus my thoughts and keep this brisk, I'm going to cover the mechanism/experience from two angles. The three best reasons to use multi-use cards, and the three best reasons to not use multi-use cards.
Let's start with the not. <insert Wayne's World reference>
The Three Best Reasons to Not Use Multi-Use Cards
1. Complexity: Games with multi-use cards are more difficult to learn and play. Full stop. Every variable you force a player to learn requires more mental energy for them to understand the ramifications of their choices. Some players are okay with running a few computations and moving forward. Personally, I can quickly scan several variables, make a good estimate, and move forward. This is why I'm usually pretty good on my first play of many games, and why I'm usually quite good at games like Libertalia.
But, many players aren't comfortable with this. They want mastery of every choice and you'll see AP slowly choke them into a dark pit. You can support your decision by keeping your central rules very simple. In Five Ravens, you basically play a card for its action or number. You choose point cards based on higher number first. By keeping these simple, it makes the meat of the true decisions - how to build your tableau and why - a little more manageable. With SPQF I simplified it even further: use this card for its action or for its modifier. I think this is why people pick up SPQF faster!
Players' cups always runneth over with rules. Multi-use cards are a VERY quick pour to this cup. As long as you know you're spending most of your budget upfront, well, that will help. I try to follow a few rules of thumb.
At most, your cards should have three functions, but really, keep it to two.
Never go beyond five cards in hand! And if need be, consider fewer cards, though understand Dominion has trained us all that a hand equals five.
Try not to mix overt functions - initiative or action - with subtle functions. In Farmageddon, cards can be used as Fertilizer, a Crop, some for their action, some to discard to pay for stuff, and some to combo with certain cards. While I think it makes the game really fun, it also makes it busy. Try to use the same part of the brain for both uses!
The fewer parameters in your game overall, the better. With SPQF, most things are built around gathering resources, storing resources, spending resources on your tableau, or gaining VP. Because of this, it's easier to process the mult-use cards. They only go towards a few things!
2. Tough to Tune: Getting a game from F to C is honestly pretty easy if the idea is solid enough. You're basically clipping away obvious thorns. From C to B requires some insights, more testing, and experimentation. If you make it to B, getting to A is often just a matter of duration and diligence. If you're annoying and dogged, your game will sit on command. But that A+? Man, that's tough. There may be a single card that leads to a dominant strategy, or a pairing of cards that only emerge 1/10 games, but when they do, everyone hates the game and you can't figure out why.
Tuning can be hard. When all of your cards (or components) can do multiple things? Well, the matrix of work just expanded exponentially. Multi-use cards should be avoided if you don't love the number crunching and the final grind of tuning. You should avoid them if you don't have a test group that'll play dozens or more times. You really need to know your game. The surface observations of a drive-by tester won't be your salvation.
I recommend you create a spreadsheet with Excel or Google Sheets that lets you quickly examine your spread of cards.
I recommend you always personally play strategies you think are too weak to see if you can make them work.
I recommend at the outset you give your cards, or groups of cards, a reason to exist. I often find theme is a really good assistant here. With SPQF, while the theme will seem thin to most people, all of the cards have a purpose for existing. There are engineering cards for construction. Military cards to quickly recruit, downsize, and "raid" resources cheaply. If you group your cards thematically, that naturally puts restraint and binders on them. Right now, no military cards in SPQF help you build. They have an approximate use. If you give all of your cards a binding, a purpose, it helps you reign them all in and keep them consistently powerful.
Finally, try to make sure that if you stick to the two uses I recommended above, try to make one relatively binary or static. For example, in SPQF, the modifier function has no rules or tuning. The spear modifier is no better or worse than the sickle. They just enhance certain cards by +1. This means my variables to tune are the actions, but not the actions AND modifiers.
Just because you're multi-use doesn't mean you need to be anti-simple.
3. Less Predictability: If every card can be used in two or three ways, you will quickly see players craft interesting strategies. You will see things you didn't anticipate. You will see people exploit and break your game, conceive counters, and evolve the design past your original intentions. I love this. In the first play of Dungeon Time, Fun! a co-op I'm working on with Joshua Buergel, Miotke assumed that heroes passed with the Bard also resolved. I hadn't thought of that, but it was really interesting. When I first introduced Crop Insurance in Farmageddon, one tester asked if they could kill their own crop to gain the money, which was more than the value of the crop. I hadn't considered that, and it was not only fun, but funny.
Some will revel in this playground. But, others will be put off by the sheer variance in your game. They won't like how difficult it is to ascertain the intentions of opponents. Or, the multiple paths to an objective. As above, you need to consider a few key things.
You'll need to confine your player interaction so that it doesn't quickly aggravate. People are okay with their opponents doing things within a known sphere. I think one of the reasons Fluxx or Munchkin frustrate so many gamers is that the game feels so unpredictable and arbitrary. Therefore, if you give players multiple ways to solve problems, you'll need to limit how many ways they can interact with each other. Use a peaceful method of interaction, perhaps.
You might also want to limit the length of the experience. High variance in a short amount of time is interesting and will ideally lead to repeat plays. But in the same way high randomness has low appeal in a really long game, a game with such immense variance is going to be more difficult to pull off with a longer experience. Of course, there are masters who do this. I'm just recommending guidance!
Finally, consider contextual triggers and functionality. If a card grants a global power that can always be used, the possibility space expands rapidly. But, if you say "if this is true, do this," then the card isn't always valid. For example, in SPQF I have several cards that trigger off having stored resources. This means you have a goal - to store resources - but if that isn't the case, the resources have no rules, and you can ignore those cards.
Let's move to the positive side.
The Three Best Reason to Use Multi-Use Cards
Hint: These are oddly a mirror image of why not...
1. Potential Solve for Tough Tuning: Using multi-use cards really clicked for me designing my first game, Farmageddon. I had a problem. I had the idea that you'd play Crop cards that were worth points. You then had Fertilizer cards you'd use to Fertilize them, which let you harvest them. They were distinct cards. On your turn you'd draw a few from the deck.
But, after several tests, I had a problem I couldn't seem to solve: players either had too many crops, or too much fertilizer, but never the right amount.
So, what if they could be used for both? It worked instantly and it blew my mind.
In SPQF, I could create modifier only cards, but it would be so hard to coordinate those functionally in your deck. In Cry Havoc I could have Resource cards and Tactics cards, but what if you only drew one and not the other? I'm cherry picking here, but adding a few twofers to your design will plug a hole that a perfect distribution never can. The thing is, probability is a cruel, fickle, insulting mistress. Just look at Magic: The Gathering. Yes, the game is amazing, but I find the Land draw issue to be a deal breaker as a casual player. Losing, or winning, because I didn't draw a reasonable number of them just kills me. I've heard Richard Garfield make several excellent arguments for why it is still the best solution, but I still find it frustrating.
The next time you find you cannot quite get your tuning to work, try to give your cards a second function that addresses the issue. Discard X cards to gain one resource. Bid cards for turn order. Whatever. See where it leads you.
2. Choice: I love a hand full of opportunities. It's intoxicating. There is a moment in Broom Service or Glass Road or Libertalia when I look at my hand, have the world's best plan, and find myself standing up in eagerness to take my turn. If you turn 5 cards into 10 options with a multi-use solution, you're going to make some players estatic. Now, as mentioned far above, you're making your game more complex. Less predictable. Harder to play. But, for some of us? It's the thing that turns a game from like to love. Make games people love. This may not be the solution, but it is one potential path to drive your game towards an eager niche.
3. Because it's Hard: You should design things that push you. That force you to learn new things, or leave your comfort zone. Multi-use card designs create a few such opportunities. When designing initial content for your game, pending the design, you'll need to design more elements for each card. With Five Ravens, though the game had only nine cards, I had to design 18 powers, and they had to be cohesively crafted in pairs.
If you want your cards to have three global uses, using only color, number, and icon, you need to think of three, simple, intuitive ways to do so. It really makes you think.
When making a multi-use card game, which we discussed is more complex, you really need to compensate by designing cards with simple, clean layout. Designing actions that are intuitive and clear. Crafting overt goal systems. Creating modes of interaction that are restrained, yet meaningful.
Multi-use cards bring SO much baggage to the table. They are a pain, some people hate them, and some people have strong opinions. The fingerprints of Chudyk and Race for the Galaxy are everywhere. Can you stand out? I'm not always sure I can, but I love to try.
I think you should use them because they make everything harder. They're a pain in the ass. And I think they'll push you to create something interesting. Even if you don't ultimately use this game, they'll open your mind to a new way of thinking.
I love multi-use cards. Hopefully, this is useful for you if you intend to use them as well. Or, perhaps it leads you to think about your own favorite mechanism?