Hyperion Voyages uses a number of variant systems (some of which are heavily inspired by other sources) that are pervasive to this campaign setting and should not be removed. Exceptions and clarifications to each imported variant are written into their descriptions to fit in with rebalancing and so that they mesh well with eachother and the setting.
How it Feels for the GM
The GM must be willing to adapt their gamemastering style to the cold hard reality of how caster-archetypes work in D&D 3.5e.
First, your world must recognize that caster-archetypes (magic, psionic, or otherwise) are dangerous much like someone with a concealed and loaded military-grade automatic assault rifle is dangerous in the real world. They could be anywhere, and in some cases they can’t be truly disarmed. NPCs should generally feel uneasy around caster-archetypes, and even podunk local law enforcement should have caster-archetypes in their equivalent of SWAT teams and patrol squads.
Every NPC must have grown up learning as common sense that if you’re fighting a group, take out the caster-archetype’s first and as quickly as possible, preferably before the casters can unload their first volley or start healing their friends. Counterspelling healing spells is a basic but effective NPC tactic. NPCs must use line-of-effect and line-of-sight to their advantage in the same way that having cover matters in modern first-person shooter games. Access to caster-archetype classes may in some cases be thematically restricted (but not forbidden from PC use) and monitored by law in the same way that mutants were “registered” in the X-Men franchise.
Second, your quests must be designed to give the party a sense of urgency in their task, or everything you as GM do to balance the game will be for naught. The largest design flaw in D&D 3.5e is a concept called the “15-minute work day”. Many RPG groups run their party until the caster-archetypes drain their metaphorical batteries (which takes roughly 15 minutes of work in “game time”) and then they all stop and sleep for the “night”. This would have terrible in-game implications, as in reality everyone (especially the villain) has a timetable of plans that they’re working to bring to fruition as soon as possible. They won’t screw around, and neither should the PCs. You must — through quest design — force the prepared-type casters (wizards, clerics, druids, etc.) to feel like they have to leave spell slots open (decreasing how many spells are at their immediate disposal) or pick more versatile and underpowered options, or otherwise they risk becoming near-useless later on.
How it Feels for the Players
If you’ve played D&D 3.5e before, this will almost feel like you’re learning an entirely new game system that just happens to be compatible with everything written for D&D 3.5e. If you’ve never played D&D 3.5e before but have played 5e, imagine that the proficiency bonus was split up into two-dozen specialized bonuses, and you had to upgrade each one individually, and you’ll get D&D 3.5e. Then on top of that, imagine D&D with superheroes, hackers, corporate espionage, and space-travel.
Unlike normal D&D 3.5e, Hyperion Voyages forces a more “realistic” approach to rolling and information control. Getting stacking temporary bonuses is more important in this setting than getting small permanent upgrades, and you’re given tools (bennies and action points) to spend on yourself and on the other PCs to give those bonuses, on top of your own creativity for finding them.
You have a lot more options to customize how you accomplish an action, but if your character couldn’t know the result (like for a Hide check), the GM rolls it instead. However, you roll some of the things the GM would normally roll, and your rolls are less swingy (unless you want them to be swingy) so you can rely on getting at least rolling an 8-12 on every roll. The thrill of rolling a natural 20 will happen less often, but the frustration of botching will also happen less often.
It’s a bit of a gritty setting, but not too gritty. Remembering to “double-tap” will sometimes be very important. Having a medic handy (or at least a doctor who gives you a discount) is vital for survival, but healing magic isn’t quite as important. If you’re playing a game with licensed “Adventurers”, it’ll feel like you’re The Avengers (although far less powerful than them). If you’re a spellcaster, NPCs will treat you like an oppressed and feared minority (because of your immense mystical power), and if you’re a psionicist then people will look up to you as a paragon of Hyperion society. There will be times where your character becomes so stressed that they can’t handle the situation.
Regardless, you’ll almost-always feel like you’re in a rush to save a princess or stop the villain. Villains will feel more nuanced because they consider themselves to be the heroes, and they’re in a rush too. You’re going to feel like bad-asses with guns and power armor, the exceptional ones called in to do what no one else can. You have so many defenses and benefits working in your favor compared to normal D&D 3.5e that smart play is rewarded handsomely, but the game is still pretty lethal.
These variants apply to everyday adventuring and are the bulk of what makes this game feel the way it does.
- Action Points: Similar to 4e action points, but much more versatile.
- Armor As Damage Reduction: You can choose to buy armor that gives Damage Reduction (DR).
- Bell Curve Rolls: Average rolls become more likely, fringe rolls become less likely.
- Complex Skill Checks: Similar to 4e skill challenges. There are also complex ability checks.
- Death And Dying: Dropping to 0 HP means making a Fortitude save to avoid falling unconscious or dying.
- Defense Bonus: Class level bonus to Armor Class (AC), alternative to armor.
- Game Clock is Different: Villains express their timetables in days instead of weeks or months.
- Item Rarity: Shopping for rare items or buyers is now uses the Gather Information skill.
- Passive Checks and Saves: Get free information from the GM without prompting, based on your PC.
- Pathfinder Combat Maneuvers: This includes grapple, disarm, trip, etc. and some minor additions.
- Players Roll All The Dice: Gives the players more control over what happens.
- Reserve Points: Similar to D&D 4e healing surges, but also triggers automatically.
- Roll Control: You can significantly manipulate what dice you roll.
- Save Points: This makes saving throws at least partially a gradual defense.
- Skill Advantages: In various circumstances you’ll add your number of ranks in a skill to a roll.
- Strife: Intelligent creatures get stressed and may even flee a stressful situation.
- Variable Modifiers: You can “press your luck” to swap out your modifier for more dice.
- XP is Different: XP rewards, character progression, and inspiration are handled differently.
Character Building Variants
Characters are built a little differently here.
- Assisted Ability Score Rolls: Roll your ability scores in-person and get what you get.
- Unrestricted LA+0 Templates: LA+0 templates are restricted, with 3 exceptions.
- Gaining Fixed Hit Points: You never roll for your HP, you get a set amount each level.
- Pathfinder-Style Character Building: This setting borrows a few improvements from Pathfinder.
- Fractional Base Bonuses Without Boosts: Multiclassing is stronger through fractional progressions.
- Mundane Characters Gestalt: Weaker classes can merge together similar to old “dual-classing”.
All things non-mundane have had a major overall.
- Energy Recovery Overview: Non-mundane energies are recovered very quickly.
- Daily-Use Recharging: Abilities marked “per day” recover when you rest a short period.
- Increased Essentia Capacity: Incarnum characters get some much-needed relief.
- Infusion Points: Artificers now manage their abilities through a simple points system.
- Meldshaping is Different: Incarnum is a different form of energy, although there is a little overlap.
- Psionics is Different: Psionics is a different form of energy too.
- Spell Points: Spellcasting has changed drastically and now uses a highly-thematic points system.
It is highly recommended that you use certain house rules when playing with this setting.