First, I'm going to talk a bit about my philosophy of skills.
Some skills are basic, immediate things, that any character who wants to do things should have. For example, if you want to beat the hell out of someone, you should have Boxing. It gives you a straight-up, linearly increasing bonus to-hit. This compensates for the fact that an Immortal gets a slightly less favorable to-hit advancement than a B/X Fighter. Some of these skills are so essential that characters need to have them outright. Multitasking, for example, is the skill that most contributes to Immortals being better starship pilots than the typical crew. Getting more action cards gives you more options for when you can act, even before you start getting other kinds of bonuses and access to extra actions per round.
Other skills are more like what a skill means in a normal RPG. The basic Science skill, for example, means that you know science stuff in a vague and hand-wavey sort of way. I actually don't like that. My goal for skills is that they give fairly definite and mechanistic (if not mechanical) benefits. A magic user in the old school who wants to do spell research doesn't have to make a lot if intelligence checks or have a spellcraft skill; their chance of success is based on time, money, and their level. That's how I want it to work. If you want to bio-engineer a duckbunny, I don't want the Referee to have to make up a lot of difficulties and for you to have to roll skills to do it. Really, it should be more like:
1. You need this amount of lab equipment (This is actually a great kind of requirement, because it means the PCs have to set down roots somewhere, maybe guard their facilities, etc.
2. You need certain skills (again, I want there to be a mechanistic requirement.)
3. You need the two critters to be melded together into an abomination of science (easy for a duck and a bunny, could be an adventure hook for anything more interesting.)
4. You need a certain amount of money in supplies or whatever (Keep the characters poor and greedy at all times!)
And then poof, there's a duckbunny. Maybe there's a check that isn't too hard, and you can roll every week until you succeed. Or maybe it just takes 1d4+1 weeks. Give the player some variance so they can't plan everything precisely. Unless they've made a duckbunny before, or hacked a corporate mainframe and stole another scientists' work. If it's the former, this is too boring to be worth time. if it's the latter, you've already got an adventure hook out of it and you can just let them have it.
Skills come in hierarchies. I'm going to use Science as an example, but there are certainly more different skills than that.
The basic Science skill doesn't do much on its own. It's a way for the Referee to hand out information. If a player finds a weird phenomenon floating out in space and they have Science IV and nothing else, the Referee shouldn't give them a lot of data. "It's some kind of gravitic-dimensional vortex. You don't have any idea what it might do, but it's at least potentially dangerous. You can use your ship's computer to store the readings you're getting. You could possibly sell the data, but you don't know what it is or what it's worth. If someone wants to do some research you could find a professor of dimensional mechanics or someone like that to do a consultation with...or you could just throw an avatoid in a vacc suit through it and see what happens." (Suggestions like this are good, because they give the players a sense of the setting and context. Also, the players often come up with the best plans when they are like "Well, that is bullshit, we'll do something totally different and throw the referee a curveball.")
Science makes a good introductory skill because it's a cheap Factor I skill that has obvious RP implications. Everyone knows kinda what science is and has an idea of what someone who took a bunch of science survey courses in college should know. Or at least you could figure it out with wikipedia. Actually, that's a pretty good mechanic: At this level, you can consult wikipedia OOC to see what your character knows.
A tier above introductory skills are specialization skills. This is like Biology Specialization. It's a higher factor, it's more expensive. It lets a player who is most interested in a given part of a general skill get additional bonuses in that skill. Depending on the prerequisites, it can let them get more bonus more cheaply at a cost of general skill.
The third tier in the chain is where things start to get interesting. Third-Tier skills should be adding new capabilities. In this case, Bioengineering lets you start making your own monsters. It's not necessarily directly combat-relevant (although it could be, if you make some kind of cool war-python that you can ride on, instead of an adorable litter of duckbunnies.)
Fourth-tier skills should be major rulebreaking bullshit. They have high Factors, are expensive, have major prerequisites, and let you break the game rules by doing things like jacking up all your attributes. The skill that does that, by the way, is Clone Enhancement. If you read it, you'll note that it requires facilities, time, and money, in addition to being a Factor IV skill, and thus pretty expensive in terms of time and money.
Factor: 1, FREE
Unskilled: Human Characters with no Athletics skill can make at most one move action per round, and have Speed 4.
I: Character’s rank in this skill is added to any attempt to swim, jump, climb, play sports, etc.
II: Speed 5.
III: +1 Encumbrance Slot.
IV: Speed 6.
V: The character can make an additional Move action per round.
Secondly, you take a specialty in Dance. You only know you have to do this because "Dance Specialty" is listed as a prerequisite for competitive Dance.
Prerequisites: Athletics III.
I: Like the other Athletics specialties, this skill will simply add to any attempts to do the specialized thing. In the case of Dance, we can assume that (like most Immortal skills) it's very broad, and covers anything from formal ballroom dance to impromptu mocking jigs.
Now, the third-tier skill. This one starts opening up weird new mechanical realms. Note that none of these skills require a IV or even V in their prerequisite. We want a character to be able to buy into this without a huge time investment. For a mid-level character (level 5, 10 SP per week), you could very easily become a professionally skilled dancer in just a few weeks, and start taking part in competitions as one of the lower-ranked competitors. I personally think that Level 5 is probably around the sweet spot for campaign play. Characters should have the skills, equipment, and competence to begin doing larger and more self-directed projects. They have room to pick skills up on a whim.
Prerequisites: Dance Specialty III
Description: Any character may take part in a dance-off! They can use the skills and attribute bonuses they do possess, even if they don’t have the prerequisites to issue a challenge, or don’t have the Dance specialties. However, if they have this skill and the Challenge skill, they can Serve opponents to force a dance-off.
I: Your rank in this skill adds to any skill checks to dance. Specifically, it covers highly athletic breakdancing, or similar moves. You may Serve opponents with a dance-off challenge if you also have the Challenge skill. If you roll a natural 18 for your Move during a dance-off, you may use a special move. You gain access to the Step It Up move.
II: If you roll a natural 17 or 18 for your Move during a dance-off, you may use a special move. You gain access to the Tag In move.
III: If you roll a natural 16, 17, or 18 for your Move during a dance-off, you may use a special move. You gain access to the Denouement move.
IV: If you roll a natural 15, 16, 17, or 18 for your Move during a dance-off, you may use a special move. You gain access to the Stomp move.
V: If you roll a natural 14, 15, 16, 17, or 18 for your Move during a dance-off, you may use a special move. You gain access to the Bite Their Style move.
I'm not going to belabor how the tiers work anymore. Just know that the Challenge skill requires the first-tier Social and the second-tier Intimidate Specialty.
Prerequisite: Intimidate Specialization III
Description: This skill allows your character to issue serves to their opponents. Someone getting Served is a necessary prerequisite to forcing another character to engage in a Dance-Off, Rap Battle, or other Challenge.
I: Your rank in this skill adds to attempts to Serve an NPC.
The tradition of various kinds of Challenges evolved across the galaxy to allow confrontations between heroic characters without death and bloodshed. It’s a way for characters to show off their skill and craft and still both walk away. They are viewed as sacred, and to violate their tradition is a source of crushing shame.
The kind of challenge available in the basic game is a dance-off. This displays the physical prowess of the parties and is viewed as suitable across cultures.
The following general rules apply to all challenges:
1. The target of the challenge must be a significant character or NPC within sight and hearing of the challenger. A horde of random hobgoblins cannot be Served. If there is a chieftain among the hobgoblins, though, then the chieftain could be the target of a challenge. Heroic characters like the PCs should almost always be able to tell which members of a group of NPCs are significant enough to warrant a challenge. Unintelligent creatures cannot be served. A horde of undead is immune to service, but the vampire leader can still be served. (Vampires are incredibly vain, they will almost never turn down a Challenge.)
2. A Serve must be issued before the fighting starts. Winning initiative and using your action card is good enough, so long as no one has made any attacks yet. Serves must be in person, they cannot be done via starship comms.
3. All hit point losses are rounded up, so that more damage is taken. However, no one can ever be reduced below 1HP by the results of Shame from a Challenge. The whole point is that they are non-lethal.
4. By serving or accepting a challenge, the party agrees on a meta-game level to allow the loser to retreat in peace. The loser is not so bound. They may, if they wish, attack the winner. This is regardless of who issued the serve.
5. If retreating would mandate abandoning a valuable position or treasure, that is, if the encounter has more stakes than simply being a loser or winner and ceding the field, then the party who receives the serve may receive a bonus to resist it at the discretion of the Referee. If the balance of forces is so hugely one-sided that the stronger party believes they are under no threat, then they may automatically refuse a successful challenge without sustaining Shame damage. However, it is obligatory in this case to then offer the Challenger reasonable terms for Surrender.
6. In order to serve, the serving party need merely announce it. If the target is within sight and hearing, and is able to understand the serv, they have the choice to simply accept without rolling. Serving someone to have a dance-off can be done without a common language, Rap Battles depend on mutual fluency in some shared language.
7. If the defending party does not wish to accept Service, then the parties can roll dice. The Server rolls 3d6 + Social + Intimidate Specialty + Challenge + Their Charisma modifier. The difficulty of issuing a successful challenge is 20. For every five by which they beat this difficulty, the defender's saving throw is penalized by 2. (-2 at 25, -4 at 30, etc.) If the Servee wishes to resist a successful Serve, they can roll a save v. spell, penalized as above.
8. If the Server beats the difficulty and the Servee forgoes or fails the saving throw, they have been Served. The Servee must now either accept the challenge or suffer Shame.
9. If the Servee rejects a successful Serve, they must take 25% of their current HP in damage. ALTERNATELY, one of their allies who is present may accept the Serve on their behalf. This relieves the original Servee, and the original Server may not withdraw their challenge. You want to make sure that the other side doesn't have an incredible dancer hidden in the back before you issue a challenge.
10. Once someone has given, rejected, or accepted a Serve in a given encounter, they cannot then Serve or be Served by anyone who was party to that encounter (that is, anyone who was served or served someone, or any of their allies who were present) for a period of 24 hours.
11. Once a challenge is accepted, either voluntarily or by force, then all the action must stop until the Challenge is complete. This does affect mindless NPCs if they are led by any character who is a valid target for a challenge. The referee is welcome to interpret this as broadly as they like.
12. Unless otherwise stated, the Server acts first in the Challenge.
There can be multiple different kinds of challenges, possibly unique to the individual campaign. Dance-offs are the most universal, and are described below.
The goal of a dance-off, mechanically, is to make the single best poker hand that it is possible for the player to have. All the poker cards issued are kept face-up on the table in front of the player collecting them; everyone can tell how well someone is doing. The way to accumulate cards is to have the character successfully execute moves.
Each round consists of three moves by each involved party. Each successful move gains the player one card from the poker deck. Special moves are used in addition to the regular move that triggers them, and do not give you additional cards. The most cards it is possible for a player to have, at the end of the dance-off, is 9. The standard roll in a dance-off is a D20 + the character’s Charisma modifier + the total of their physical attribute modifiers + Athletics + Dance Specialty + Competitive Dance.
The Round: Each party to the dance-off makes the standard roll three times, in sequence. The Server acts first. Each roll is a move. The Difficulty of the roll is 25. If they succeed, then they have executed the dance move correctly and they gain a card. If they roll a special move due to a high natural roll of the die, and that roll is high enough to succeed at the current Difficulty, they resolve that immediately, before making any further normal moves. It’s the special moves that make things interesting.
Step it Up: You can use your special move to step up your game, and use more impressive moves. If you choose to do this, immediately reroll your move at a difficulty two higher. If you fail, your regular and special move both fail, and you do not get a card for this move. If you succeed, you gain a card as normal and the difficulty for all moves after this are increased by two, for all dancers involved in this dance-off. This special move can be used multiple times by multiple dancers. It allows highly skilled characters to shut less-skilled characters out of the competition.
Tag In: You tag in one of your teammates. This does not require a roll, but the teammate must be willing. Immediately put your hand of cards (including the one from the move you just made, if it was successful) in between you and the teammate you just tagged in. In the final hand, either you or your teammate can use any of the cards in this common hand (this is very similar to Texas Hold ‘Em.) Any cards you earn after this division are yours only, and any cards your ally earns after this division are hers only.
Your teammate will take a turn (all three rolls) at the end of the round, and at each round thereafter. This Move is most successful when used in Round 1 with a highly skilled teammate. When you use this move, one of your opponent’s allies may immediately step up as well, with no roll required. If so, your opponent must divide off the common cards for their side in just the same way that you and your ally did.
Denouement: This special move may only be used during Round 3. Make a single Move roll, directly opposed, against any opponent currently participating in the dance-off. The winner may switch any one of the loser's cards with any other card that is currently in play.
Stomp: This can only be used if you have the agreement of a majority of your allies to use it, and requires a natural 18 regardless of what numbers you normally gain special moves on. Make an additional Move roll against a difficulty of 35. If you succeed, Shame will apply to everyone on the field who is party to the conflict. If you win the dance-off, all enemies suffer Shame. If you lose, you and all of your allies suffer Shame. Whether you succeed or fail on this roll, your opponent may immediately use the Tag In maneuver on any three of their allies, or alternately draw three more cards for themselves and keep them face-down. If there are already multiple opponents tagged in, the face-down cards can be used by any or all of them to form a hand at the end of the dance-off.
Bite Their Style: When you choose to use this special move, do not draw a card immediately. Instead, choose an opponent and roll 3d6 + your Wisdom mod + Cold Read against their roll of 3d6 + Charisma mod + Deceive Specialty (if they have it. Social does not count.) If you succeed, you can figure out your opponent’s dance strategy and pre-empt their favorite moves. Draw a card normally, and your opponent needs one higher number to get a special move result. For example, if they would normally need a natural 17 or 18, they now need a natural 18. On a failure, you do not draw a card as you flub the move.
This can be used multiple times on a single opponent. It can result in an opponent being unable to use special moves at all. Once you fail using this move, you cannot use it again for the rest of the day.
Finishing the Dance-Off
Determine which player has the best hand using normal poker rules. That player chooses which if any of the other characters who participated in the match are to suffer Shame. Shamed characters lose half of their current HP, rounded up. This cannot reduce any character below 1 HP. This is not considered to be taking damage, and no Armor, Shields, or other normal methods of reducing damage apply. At this point, the losers must be allowed to slink away by the winners. Jeers may be directed their way, but no hostile spells or other actions. However, if the losers decide to attack anyway, they may. Their names may live on in infamy, but this does not garner them any additional Shame (at least not of the kind that is mechanically represented by HP loss.)