Skill suggestions

[Vanguard]

Hey everyone,

I'm working on filling in all of the player abilities that will be available in my game, and I have to decide on which ideas to add, and which ones to cut out, so I'm going to ask for advice here.

Firstly, I'm dividing all of the active skills in the game between magic skills and physical skills, and there will be exactly 26 active skills of each type, so that using any given skill can be done as efficiently as possible (pressing 's' or 'm' and then the letter of the alphabet corresponding to the skill you want).

You'll be able to put points in each skill, and every level of a skill will unlock a new ability.  If you've played ToME, it will work a lot like the magic skills do in that game.  Generally the lower level skills will be designed to be more versatile and useful with a variety of character builds (as an example, the level 1 and 2 evocation skills will be useful to both magic users and fighters, but the level 7 evocation ability will be too costly to use without a fair investment in the willpower and concentration attributes).  Ideally this will lead to hybrid characters being just as viable as purely specialized ones.  My main focus right now is to make abilities that are fun, versatile, and interesting.  Balancing will come later.

Anyway, like I said, I'm trying to decide what to keep and what to cut.  For the magic skills what I'm considering are:

Enchanting, or the manipulation of physical objects.  This will include buffing yourself, items, empowering your attacks and other abilities, and cursing your opponents.  An ability to enchant floor tiles in order to set a sort of trap is also being considered.

Evocation, or the manipulation of energy.  This will include a straight damage spells, a passive defensive ability, and a weapon buff.

Illusion, or the manipulation of the senses.  This will mostly include various methods of hindering your opponent that are less direct than the offensive skills in evocation (ie, they're not direct damage).  In addition, it will have abilities to make your attacks harder to dodge, and enemy attacks easier to dodge.

Kinetics (Kinesis?  Telekinesis?  Name suggestions are welcome), the manipulation of physical forces.  This would be mostly a hybrid of evocation and debuffing.  It would include skills that can push back or otherwise reposition enemies while doing damage at the same time.  Movement and defensive abilities are also something I'm considering.

Biotics (Biomancy?  Biology?  I'm having a hard time coming up with a name I like for this one as well).  Anyway, this would include abilities that directly affect living things, probably a something like a combination of enchanting and evocation.  It would do damage through poison and such.  I don't want a very strong focus on healing magic, so there would probably be only one or two healing spells in this tree, and none anywhere else (the focus will be primarily on preventing, mitigating, and enduring damage instead, so a character with no healing abilities wouldn't be severely disadvantaged).  The spells in this tree would only function on living targets (not constructs and such), and I'm thinking that the level 7 ability would be instant death to a single living target.

Anyway, with 7 skills for each of these, that would leave me with 35 skills total, which is more than I want.  If I cut one of them, I'll be left with only 28 skills.  With two of these being passive abilities, I would end up with the desired number of 26.  The first thing I want to ask is how interesting each of these sound, which ones sound more useful and fun to play, and which one should be cut.

The second issue is the physical skill trees.  I think I know which skill trees I want to use, but I'm having a hard time coming up with interesting abilities to populate those with.  The skill trees I'm going with are:

Combat techniques/Weaponmastery, which will contain abilities for a hand to hand fighter.  I'm going to shy away from the typical "this skill does +5 damage," and "this skill does +10 damage, but with 25% less accuracy" type of things because those are boring.  I think for the most part I know what I'm going to do with this.  One idea I'm still toying with is a combo attack ability that lets the player continue hitting the enemy in a single turn until one of their attacks misses.  Each subsequent attack would have lower accuracy so a high agility character couldn't make infinite, certain death combo attacks.

Marksmanship will have various special effects for ranged attacks, and I think the main focus here will be debuffing (leg shots for reducing speed and such).

Athletics will have abilities that aren't directly attacks, such as a running skill that lets the player trade some of their stamina in order to move twice in one turn, and an ability that lets a player move past enemy occupied squares or switch places with an adjacent enemy would be useful too.  I'm having a hard time coming up with enough ideas to fill all 7 skill slots though.

Tactics is what I think I'm going to go with for the name of the last physical skill tree, and I'll probably fill it with miscellaneous ideas that wouldn't really fit anywhere else.  One thing I'm considering doing is adding stances, which are sort of buff abilities where only one can be active at a time, but they offer a permanent bonus (maybe accompanied by a negative trait) until the player switches to another stance.  Does that sound like a good idea?  Would it be fun or interesting?  I'm open to any other suggestions.

There will also be some skill trees that will be completely passive, but those weren't mentioned, because they'll be much more simplistic, and won't add towards my goal of 26 active skills for each type.

So does anyone have any recommendations or ideas I could use?

[Krice]

What is the point of having exactly X number of skills? It looks like you want to add skills and then try to think how they could be linked to the gameplay, but that's exactly the wrong way to do it. The right way is first design the basic gameplay and then skills, which should be linked in real gameplay actions.

[Vanguard]

The reason, as was mentioned above, is so there's one for each letter of the alphabet to keep it convenient.

[Etinarg]

Your list is huge already, I don't think I can give a lot of suggestions for more ... if you get like 25% of your suggestions actually implemented it will be huge already, I think.

A few minor ideas:

Summoning/Necromancy: Rise or summon helpers.

In the Biotics section, there could be symbionts, or symbiosis skills to merge two life form into a new one, with combined skills of the two - or some sort of mutual benefit.

Also, some non combat skills maybe, cooking, tayloring, crafting. Fishing and mining?

Gods, spirits and prayers? Can maybe go in one of the sections.

Sorry if I suggest things that are in there already. It's quite huge what you have already.

[AgingMinotaur]

As Hajo said, your planned framework is already

huge

so I don't think you need lots of more ideas before you start implementing this.

Biotics, what to call it? My first association would be something like "animism", but I guess that connotes the productive forces of life, the stuff bland D&D-like druids do. But maybe "witchcraft", "hexing", or something. You could even theme it with some typical withclike powers, like "polymorph to toad".

Kinetics: Telekinesis is at least a better name than kinetics, since it actually means what you intend. But I agree it's kind of dull. Maybe you could just give it a neat theme, eg. "voice magic", where each power is a "word of force" that you shout out to shatter walls, spring traps and open hidden doors, smite your enemies, etc. Or something

Athletics: You already mention switching place with a monster and "jumping" (over an enemy, but even over a trap may be useful). If the physical skills are supposed to be counterparts of the magical ones, ie. represent heroic "paths", you could expand athletics to include semi-mystical feats of speed/movement/body-mind-coordination. Stuff like phasing through walls, or even fakir-like buffs (temporary immunity to walk through fire) could fit the bill.

Just some stray thoughts, since you ask.

The right way is first design the basic gameplay and then skills, which should be linked in real gameplay actions.

Not necessarily. If you want to make "a clone of game X, with Y and Z added" (yawn, next-gen vapour-yawn ), I might agree. But some interesting features might require that the basic gameplay look different, and then, it's better to plan ahead.

As always,
Minotauros

[BirdofPrey]

Why is it more convenient to have 26 skills represented by a-z than say, 10 skills represented by a-j ?

Just my opinion, but 52 trainable skills seems a little bit over the top.

[Vanguard]

Summoning/Necromancy: Rise or summon helpers.

Gods, spirits and prayers? Can maybe go in one of the sections.

For thematic reasons, I'm going to avoid things that would prove the existence of spirits, deities, the afterlife, or any other supernatural forces in the game.  Yeah, there'll be magic, but it will be ruled by its own laws of "physics," so to speak, and it'll come from the individual using it rather than being the result of a pact with a spirit or a blessing from a deity.  If you come across an animated skeleton, it'll most likely be manipulated marionette-style by an enchanter instead of being a vengeful spirit or anything like that.

Similarly, you won't get any light or dark element attacks.

Athletics: You already mention switching place with a monster and "jumping" (over an enemy, but even over a trap may be useful). If the physical skills are supposed to be counterparts of the magical ones, ie. represent heroic "paths", you could expand athletics to include semi-mystical feats of speed/movement/body-mind-coordination. Stuff like phasing through walls, or even fakir-like buffs (temporary immunity to walk through fire) could fit the bill.

I have nothing against superhuman abilities for non-magical skills, just not supernatural ones.  Basically it's fine with me if the non-magical skills allow the character to do things better than any real person could, but it should still be something a real person could do to a lesser extent.  Bench pressing 2,000 pounds and jumping 10 feet high are alright, but I don't want phasing through walls and such.

Just some stray thoughts, since you ask.

I appreciate it.

Why is it more convenient to have 26 skills represented by a-z than say, 10 skills represented by a-j ?

Just my opinion, but 52 trainable skills seems a little bit over the top.

Bear in mind that included in the 52 skills will be every spell the player can use in the game.  ToME has 60ish spells, and according to its wiki, Crawl has 167.

[Etinarg]

Similarly, you won't get any light or dark element attacks.

I guess you use light and dark in the Jedi sense here ... the absence of light (darkness) can be an interesting attack spell, also a blinding flash of light.

Also effects like absence of sound can make for quite interesting effects, since it disrupts communication between enemies, and also disrupt detection of many events that cannot be seen, but would be heard.

Edit:

Expanding on this idea, there could be a "channelling" skill, that uses properties of nature like light, warmth, also environmental sound, and either pulls those from the environment to focus the effect in a small area, or the reverse, steals the effect from a small area by distributing it over a large area.

For example, a channeler could freeze an enemy, by drawing the warmth from him, and disperse the warmth in the environment.

Or he could gather sound from the environment, and channel it into a stunning cacophony of noise at the targets location.

[Z]

I guess you use light and dark in the Jedi sense here ... the absence of light (darkness) can be an interesting attack spell, also a blinding flash of light.

Also effects like absence of sound can make for quite interesting effects, since it disrupts communication between enemies, and also disrupt detection of many events that cannot be seen, but would be heard.

Crawl has a "Silence" spell: "eliminates all sound near the caster. This makes reading scrolls, casting spells, praying or yelling in the caster's vicinity impossible. (Applies to caster too, of course.)  This spell will not hide your presence, since its oppressive, unnatural effect will almost certainly alert any living creature that something is very wrong." Darkness is used in ADOM (although it works in an unnatural way) and blinding light too.

I think such spells would fit as Illusion Magic in the given structure. Are forms of divination (e.g. Magic Mapping) included in Illusions?

After once playing a P&P RPG which included powerful illusions, I wondered whether powerful illusory magic is possible in a roguelike. Powerful wizards casting illusions wielding illusory weapons causing illusory wounds (so that the victim does not know which one is real even when he is wounded...) Seems very hard to implement.

[AquaTsar17]

Powerful wizards casting illusions wielding illusory weapons causing illusory wounds (so that the victim does not know which one is real even when he is wounded...) Seems very hard to implement.

That depends on how you consider illusions. For example, in the 3rd Edition of D&D there's an illusion spell that can actually kill a creature (phantasmal killer). Essentially, the illusion is something so frightening that the creature dies from being so scared. Which makes sense from a physiological standpoint: our minds do a pretty good of job of making unreal things still seem real (otherwise, horror movies and games could never be scary). So, even an illusion can have very real effects.

So how does this apply here? An illusionary creature would have infinite health, in the sense that whenever anything attacked it the attacker would get a chance to realize its an illusion and the illusion would disappear. Otherwise, it would always remain. Any damage it dealt would still be real damage, but once the creature being damaged realizes its being hit by an illusion it is now immune to further damage. That could be tricky to implement for illusionary weapons, as you'd have to keep track of whether each creature knows its an illusion. For illusionary creatures they could just disappear as soon as someone realizes they're an illusion, and single-use effects (such as an illusionary damage spell) would only do something if the target thought it was real at the time of the effect (ie: the target only receives the effect if they fail a check of some sort).

Some may consider that broken, so damage from an illusion could simply be in a "non-lethal" category. Whatever was hit by an illusionary source could do damage, but it would only ever knock a creature unconscious (if non-lethal + lethal dmg > max_health). This would imply that taking non-lethal damage at the same time as lethal damage could never kill you. Of course... if the player is unconscious they may as well be dead, since the enemies will probably still keep attacking. But it should heal at a significantly faster rate. I would recommend against having it linked to the illusion itself (so when the illusion disappears its damage effects do too) unless you have a system that handles such things for all effects. Otherwise, that could be difficult to implement.

So... I suppose illusions could be hard to implement depending on what you want, and what you consider "hard to implement".

[Vanguard]

If I go with illusion, it'll be about buffing and debilitating.  What I'm planning on for the 7th level spell in that is a completely unresistable paralysis effect (unresistable as in it would even work on the final boss).

Evocation and the telekinetic skill tree would be direct damage, enchanting would be indirect damage, and the biological skill tree would probably mostly be damage over time.

Another thing I should mention is that I don't want any abilities to ever "go out of date" so to speak.  The level 3 evocation skill won't be as powerful as the level 7 evocation skill, but it'll have a better damage:magic cost ratio to make up for it.

Edit:  Here's a bit of information about how the game will work, before I go on.

The player will have 6 attributes and a bunch of skill trees.  Every time you level up you'll get a handful of attribute points, and one skill point.

I'm considering how many skill points each level of a skill should cost.  I'm planning on a level cap of 50.  The two schemes for how many skill points each level of a skill should cost I'm considering are:

1,1,1,2,2,2,3 and
1,1,2,2,3,3,4

The former would allow the player to max out 4 skill trees at level cap, and the latter would allow them to max 3 of them.  I want the player to have to commit to getting the higher level skills, and I want them to have to make choices as to what skills have to be excluded.  At the same time though, I don't want too much time to pass where they don't get any new abilities, and I want the player to have enough freedom to get creative with their build and remain effective.

The six attributes are:
Strength: Determines hand-to-hand damage, inventory weight limit, and weapon weight limit.
Endurance: Determines health and stamina (max health and max stamina are endurance x 10).
Agility: Determines ability to hit and dodge.
Speed: Causes your turn to come up more frequently.
Willpower: Determines maximum magic points (willpower x 10), and magic damage.
Concentration: Reduces the cost of magic abilities.

Anyway here are a few ideas.  Tell me if you think these would be fun to use, and if they sound like something you would add to your character's build.

Tactics
Counterattack (passive): Gives the player the ability to counterattack.  This triggers when an enemy fails to hit the player with a hand-to-hand attack by a certain margin (say, if their attack still would have missed even if they had +50% more accuracy, the player counters).
Recuperate: Exchanges some stamina for health.
Tackle: A hand-to-hand attack that causes damage and paralysis status on the target.  The duration is increased by the user's strength, and decreased by the target's endurance.  Maybe very large endurance values (representing physically very large enemies) would give immunity to this.
Throw: A hand-to-hand attack that sends the target a few tiles in one direction and does damage.  Distance/damage are determined by the user's strength, and the are reduced by the target's endurance.  If the target is too heavy for the user (ie, too high of an endurance score), the skill fails completely.  Maybe extra damage for hitting a wall or another character?

Anyone have any ideas somewhere along these lines?

Athletics
Dash: The user moves two spaces on their turn instead of one.
Sprint: The user moves three spaces on their turn instead of one.
Jump: The user bypasses one tile, so long as it is not occupied by a wall, and lands in the next tile in that same direction, so long as it is not occupied.
Displace: The user changes spaces with one adjacent hostile target, just as they would normally be able to do with a friendly target.

I'm having a real problem coming up with something interesting for this one.  Being able to move two or three spaces in one turn is very useful in a roguelike, but it's also a pretty boring ability.  The ideas above are also pretty samey.  They don't have to be related to movement but I'm having a hard time coming up with much else that could fit here.  The skill tree is supposed to just be a general fighter/non damage tree.  I guess a dodge buff or something like that would be okay?  I think my problem is that something that would be cool in an action game, like the ability to do backflips off of walls or something, isn't as interesting in a roguelike, where it effectively amounts to "if the user is adjacent to a wall, they move two spaces away from that wall."

[AquaTsar17]

I think my problem is that something that would be cool in an action game, like the ability to do backflips off of walls or something, isn't as interesting in a roguelike ...

First, think about why it would be cool in an action game. Is it because of the animation of the character performing the action? Is it because of what the action means for the player? Or is it because it's something the player wouldn't expect to be able to do in the game?

Athletics, as a skill tree, would include things such as running, jumping, climbing, etc. There's no reason why those skills should not be included. The trick is, how can the player use them? A wall jump that moves them two spaces away isn't particularly interesting... unless facing is involved, and then the wall jump could get the player behind an enemy for a strike in the back.

Jumping could be an incredibly important skill if there's pits or chasms in the game. Being able to jump over the pit rather than, say, expending items or magic to somehow bridge (or teleport or fly etc) over it is a huge advantage. Likewise, jumping onto an enemy should give a bonus to damage, making it a very effective melee option. You could shoot the enemy for a bit until it got too close, then switch to a hammer and jump-attack them.

If you have water, swimming should be there too so players could cross water or fight in it with less difficulty. Climbing would be good if you had scalable walls. Running could give a bonus to a charge of some sort, doing more damage if you can run in a straight line into an enemy (or a door or something breakable).

Basically, skills like athletics are only meaningful in a game if they're useful. Most digital RPGs don't bother including skills like climbing or jumping because the game never includes anything which would require it. So, your game has to have situations where those skills would be needed. However, keep in mind that if players may choose an athletic skill but don't have to, then there must be alternative options. If there's a chasm with an item on the other side, the player who has jump will happily use it. But the player without jump is out of luck, unless there's some other way to get there (even if they don't have it right now). Without a way to get to that item, the game becomes unfair to the players who did not pick jump.

[Vanguard]

First, think about why it would be cool in an action game. Is it because of the animation of the character performing the action? Is it because of what the action means for the player? Or is it because it's something the player wouldn't expect to be able to do in the game?

I think it's mostly things that roguelikes don't tend to have, like needing fast, precise input to pull off certain moves, the lack of a third dimension (and thus, the lack of abilities that you can use while you're in the air), and reflexes not being part of the equation.

In a multiplayer FPS or fighting game if you manage to jump behind another player you can usually get a few crucial hits in while they turn around.  In a turn based game it doesn't work quite the same way.  You're right that it would be meaningful if facing were included, but I've never really liked using that in roguelikes.

Your observation is good though.  I hadn't thought about why it wouldn't work so much as I had just felt that it wouldn't.

One think I want is to have as many skills as possible be useful in fighting, even if they're not directly fighting skills.  Faster running or being able to jump over enemies could be useful in and out of combat, but something like a swimming skill wouldn't be relevant as often.

Edit:

How about I name the skill tree involving physical force "kineticism?"

How would grappling or wrestling skills work out in a roguelike?

Does a "disarm" skill that knocks the opponents weapon out of their hands sound like a good idea for a useful skill?

What about a high level athletics skill that gives the player two full turns (ie, turns in which they can take any regular action as opposed to only being able to move) for their one turn?  The one exception would be disallowing them from re-using that same athletics skill for unlimited moves.

[Etinarg]

I think it's mostly things that roguelikes don't tend to have, like needing fast, precise input to pull off certain moves, the lack of a third dimension (and thus, the lack of abilities that you can use while you're in the air), and reflexes not being part of the equation.

"Freeclimber" trait: You can jump at any rough surface, including the ceiling and stick there.

Well, if you are a mage and need to gesture for a spell, you fall again ...

But maybe roguelikes could make use of the third dimensions without too much hassle. It's just difficult to think of totally new things ... at least i use to end up with a mix of already existing ideas.

Does a "disarm" skill that knocks the opponents weapon out of their hands sound like a good idea for a useful skill?

It depends. If you need to capture the being alive, yes for sure. Also it will depend on the whole context of the game. In the usual hack and slash roguelike it only will lower your opponents damage, that is useful already, but in a wider context it can open new options. Maybe 

"The alien Gray points a deathray blaster at you. You use your whip and fetch the blaster. Wield deathray blaster [y/n]?"

I'd like that 

What about a high level athletics skill that gives the player two full turns (ie, turns in which they can take any regular action as opposed to only being able to move) for their one turn?  The one exception would be disallowing them from re-using that same athletics skill for unlimited moves.

A monk type warrior could get a free second attack upon a successful first one.

Or even an attack chain, as long as they do not fail in hitting ...

"You swing at the frendorlyte. You hit critically and the frendorlyte is stunned. You win a followup attack. Attack again [y/n]?"

One think I want is to have as many skills as possible be useful in fighting, even if they're not directly fighting skills.  Faster running or being able to jump over enemies could be useful in and out of combat, but something like a swimming skill wouldn't be relevant as often.

"Powerpoint presentation skill"
Requires: Portable beamer.

Effect: you can project powerpoint presentations in rooms of at leat 3x3 size. You have a 50% chance to confuse everyone in the room, a 50% chance to stun, a 30% of chance of lowering their sanity, and upon the third turn of using the skill in sequence, you have a 15% chance that random beings in the room will fall asleep."
 
"Ventriloquist skill"

You can make a monster of a group emit words. You have a 50% chance of confusing the group, a 30% chance that a random group member attacks the target of your skill, and a 15% chance to induce fear in each of the group."

There might be more ... depends on how serious you want to be with your game

Edit:

Silliness with the disarm skill 

"You see a wild cat."
[D]isarm.
"You try to declaw the wild cat. It bites you."

[Vanguard]

Okay, here's my preliminary skill list, let me know what you guys think.

Enchanting:
Charge: Increases the user's charge level by 1, up to a maximum of 3.  While charged, the user's next attack will do more damage (think Megaman or Mage Guild).
Power Enchant: Increases the user's strength and endurance for one day.
Quickness Enchant: Increases the user's agility and speed for one day.
Enchant Floor: Enchants the tile the user is standing on so that it will explode, damaging the next enemy who steps on it.
Curse: Damages all of the target's attributes for one day.
Enchant Item: Applies a chosen enchantment to a chosen item in the user's inventory.  Does not affect artifacts.
Hypercharge: The user's charge level is set to 5 for a short period of time.  In addition to physical attacks being empowered, spells are also improved in various ways.

Evocation:
Energy Blade: The user projects a beam of energy from their hand that can be used in place of a weapon.  The energy blade's damage is based on the user's willpower, and it deals magic damage instead of physical damage.
Energy Shield (Passive): The user can project a barrier of energy to defend themselves.  Causes otherwise lethal attacks to damage the user's magic instead of their health.
Energy Shot: Fires a small bolt of energy for small magical damage.
Ice Spear: Fires a large shard of ice for moderate physical and ice damage.  If a target is defeated by the ice spear, it continues towards the next target behind them.
Lightning Bolt: Casts a bolt of lightning for heavy lightning damage.  Always passes through targets, and may cause paralysis.
Explosion: Fires a projectile that explodes upon striking an enemy or a wall.  Deals heavy physical and fire damage.
Energy Blast: Fires an enormous beam of magical energy for extreme magical damage.  Always passes through targets.

Illusion:
Feint: Makes your weapon appear to be aiming for somewhere other than where it really is.  Increases the user's hit rate for one day.
Mirror Image: Illusionary images of yourself make the real you harder to hit.  Increases the user's dodge rate for one day.
Pain: An imagined injury causes the target to be less able to fight and defend themselves.  Decreases the target's hit and dodge rates for one day.
Blinding Mist: A black shroud of illusionary mist temporarily blinds the target.  Duration is based on the user's willpower and the target's concentration.
Cloak of Shadows: Bends light around the user, granting them temporary invisibility.  Duration is based on the user's concentration.
Discord: The target's sense are completely overwhelmed by blinding lights, screaming noise, and burning pain, leaving them paralyzed for the spell's duration.  Duration is based on the user's willpower and the target's concentration.

I need one more, and I think these skills could stand to be a bit more interesting.

Kineticism:
Force Push: The user touches their opponent and releases a surge of physical force, throwing them backwards and dealing moderate physical damage.  Pushes the target backwards a distance based on the user's willpower and the target's endurance.
Force Shot: A weak bolt of physical force, drawn from energy surrounding the user.  Deals light physical damage, and does not cost any magic.
Force Blast: A powerful wave of force throws the target backwards.  Deals moderate physical damage.  Pushes the target backwards a distance based on the user's willpower and the target's endurance.
Force Jump: The user propels themselves to safety.  Allows the user to move over a number of tiles, regardless of whether they are occupied.
Force Wave: A powerful wave of force is emanated from the user, throwing all enemies in a large radius around the user backwards.  Deals moderate physical damage.  Pushes the target backwards a distance based on the user's willpower and the target's endurance.

This tree still definitely needs work.  I'm thinking it'll be a weaker but more efficient evocation, maybe something for hybrids who want to use magic, but won't have as much energy to spare, and effects that change the position of the user and their target will be there to differentiate it a bit more.  I think I should put a defensive skill in here somewhere, preferably one that doesn't conflict with Energy Shield in any way.  I also intend to have some late-game enemies with immunity to physical damage.  How could I make Kineticism useful against them?

Combat Techniques:
Rush: The user runs forward one square and then attacks in that direction in one move.  Adds the user's speed to their strength for determining the attack's damage.
Double Strike: The user makes two hand-to-hand attacks in one turn.
Whirlwind Attack: The user makes an attack in each of the eight directions around themselves.
Overwhelming Strike: A crushing attack that adds a weapon's weight to its damage.
Lethal Strike: The user makes an attack that deals more damage based on the user's accuracy.  An attack that barely hits won't deal much more than base damage, but a highly accurate character will be able to inflict several times the base damage quantity.  Ideally this will help agility fighters keep up with strength fighters for damage.
Repeating Attack: The user continually attacks their target until either they miss an attack, or their target is defeated.  Each successive attack has less accuracy than the one before it.  Charged attacks only deal their bonus damage on the first hit (this also applies to Double Strike).

I need one more of these, and I have a bunch of ideas, but my main concern is that a full skill tree comprised entirely of ways to do damage, even if they're different ways of doing damage, is uninteresting.

Marksmanship:
Aimed Shot: The user makes a ranged attack with +50% accuracy.  Most of the very early game enemies will not be exceptionally fast or have ranged attacks, so I want early game archery to be fairly inaccurate to preserve the challenge in the face of that weakness.  With this skill, early game archers are still functional, but since it costs stamina, ranged damage won't come for free, and they'll need to mix it up with close ranged attacks as well.
Leg Shot: A ranged attack that lowers the target's speed for one day.  The effect is strengthened by the user's agility.
Double Shot: The user makes two ranged attacks.
Arm Shot: A ranged attack that lowers the target's strength for one day.  The effect is strengthened by the user's agility.
Vital Shot: A ranged attack that is always a critical hit if it strikes its target.
Paralyzing Shot: The user fires on a vital point in their target, leaving them helpless for a short time.  The effect is strengthened by the user's agility, and weakened by the target's endurance.
Deadeye: A powerful ranged attack which deals extra damage based on the user's accuracy.

Tactics:
Kick: The user makes a physical attack that deals physical damage and pushes their target back.  The effect is based on the user's strength and the target's endurance.
Counterattack (Passive): Allows the user to hit back without using a turn when they dodge a highly inaccurate hand-to-hand attack.
Tackle: The user makes a physical attack that deals physical damage and attempts to stun their target.  The effect is based on the user's strength and the target's endurance.
Throw: The user grabs their target, and hurls them in any direction.  This deals physical damage, and the damage is increased if they strike a wall.  If they strike another enemy, both receive damage.  The effect is based on the user's strength and the target's endurance.
Disarm: Attempts to knock the opponent's weapon out of their hands, by checking the adventurer's agility against their target's agility.  The target must have a non-artifact weapon equipped.

I think these are starting to come together, but could use a bit more versatility.

Athletics:
Dash: The athlete moves two spaces in one turn.  They may not attack or cast on either move.
Leap:  The athlete is able to jump over one tile and land on the other side, allowing them to bypass enemies and obstacles.
Recuperate:  The athlete is able to use their stamina to continue fighting when others would have fallen.  Exchanges stamina for health.
Sprint: The athlete moves three spaces in one turn.  They may not attack or cast on any of these moves.
Blinding Speed: The athlete has incredible speed and reflexes, and is able to use their stamina to make two full moves in one turn.  They may attack or cast in either or both of these moves.

I think I like the overall theme of this skill tree, but I still need to come up with more ideas.  I'd rather not have a skill that's exactly the same as another, except one is numerically better, like Dash and Sprint, but I'm not sure what I could/should do with this.

"Freeclimber" trait: You can jump at any rough surface, including the ceiling and stick there.

Well, if you are a mage and need to gesture for a spell, you fall again ...

That's an interesting idea.  I'm not sure how I'd use it, but it's clever.  Would a character hanging from the ceiling be out of reach of enemy hand-to-hand attacks or something?

But maybe roguelikes could make use of the third dimensions without too much hassle. It's just difficult to think of totally new things ... at least i use to end up with a mix of already existing ideas.

Yeah, same here.

It depends. If you need to capture the being alive, yes for sure.

I think I'm just going to say that an enemy was "defeated" when their health reaches 0, and you can decide for yourself whether your character's takedown was lethal or not.  At some points the game will make the decision for you (like a boss enemy that escapes after losing a fight).  If you need to take a certain opponent alive, it'll assume you did so after winning the fight, or have you explicitly decide whether to take them prisoner or finish them off.

Also it will depend on the whole context of the game. In the usual hack and slash roguelike it only will lower your opponents damage, that is useful already, but in a wider context it can open new options. Maybe  

It'll mostly be there as a method of damage prevention.

"The alien Gray points a deathray blaster at you. You use your whip and fetch the blaster. Wield deathray blaster [y/n]?"

I'd like that  

That's kind of the idea.  You'd need to use a turn to pick the thing up and another to equip it, but yeah.