We used both approaches fairly equally when designing our captains. Romeo/Juliet, Hamlet, and Prospero were all built top-down, starting with the Shakespeare character and then sketching out their mechanics from there. Rosalind, Imogen, and Titus were all more bottom-up designs, starting with a mechanic/goal and then matching it to a Shakespearean character later in development. Neither approach is inherently better than the other, but designing in one direction may come more naturally to you.
Keep in mind that you can always switch directions if you get stuck. Richard is a great example of a captain who was designed in both directions. While he originally started out as a bottom-up design (i.e. “We want to create a captain that feels like a Raid Boss”), his revised design is much more top-down (i.e. “How can we make Richard feel more like a schemer like how he is in the play?”).
Step 2: Identify the Archetype
Once you’ve nailed down the initial draft for your character, you need to identify what archetype it falls under. Using RPGs as an example, those games tend to have a “Healer” archetype, a “Tank” archetype, a “Support” archetype, etc. In the case of Captain’s Gambit, there are five archetypes that captains can fall under: Assassins, Ascenders, Devotees, Manipulators, and Dominators. Identifying which archetype your captain falls under might be very obvious. Take this captain as an example:
Custom Captain 1: At the end of Round 4, the player(s) with the most health gain a skull token. You win if you kill any player with a skull token. You lose if all the players with skull tokens are killed by any other means.
This captain is obviously an Assassin, because they win by killing a specific target. But sometimes the archetype can be harder to nail down:
Custom Captain 2: You win if the game ends and either exactly two Captains have died, or exactly two Captains are still alive.
If I had to choose an archetype for Custom Captain 2, it would probably be Manipulator. But their first win condition feels a bit like a Devotee, while their second win condition is a lot like a Dominator. So in a way, they straddle the line between all three archetypes.
If you can’t nail down the exact archetype (or if it doesn’t fit into any of the existing archetypes), you can instead think about the captain’s intended playstyle. Are you trying to make a captain that hoards lots of energy? Then it might be similar to Prospero, Richard, or Puck. Are they trying to make a captain that loves to form alliances? Then they might be like Iago or Cordelia. Once you’ve identified which existing captains are similar to your new creation, it’s time to make sure that you…
Step 3: Fill a Niche
Every new character needs to have something unique about it to distinguish it from the existing characters in the game. If it’s too similar, you risk making the new character feel bland and uninspired. Take this as an example:
Custom Captain 3: You win if you are alive and the game ends on round 12 for any reason, or if all players have 0 energy. You lose if anyone wins before then, or if a player ends their turn with 20 or more energy.
Look familiar? It should, because it’s basically just Puck with some added stuff about energy.