[RPG] How much the players can narrate in Fate? How much can be prepared beforehand by the Gm taking that into account

Fate has a much more narrative approach, less GM authority, and player-based plot control mechanisms. This can make for trouble transitioning from a more adversarial GMing environment.

Fate Core (and other recent Fate games such as Dresden) actually do a pretty good job of providing a suggested "menu" of powers and stunts for players to take; show them to your players and let those inform other stunt ideas through play, rather than trying to get the characters completely nailed down in advance the way you would have to in D&D.

To address the specific problems you mentioned:

• The "blind sniper" problem is that in Fate, it's very easy for a cooperative party to stack multiple temporary aspect bonuses on a situation, then tag them all for a single super-successful roll regardless of innate skill.

  Consider a sniper with a base skill of +0 - "has no idea what he's doing". First he hides on high ground (creating aspect "On a Grassy Knoll"). One of the other players - a tech - has made, and gives him some "Precision Armour Piercing Ammo", with suitable aspect. Then another player jumps into the road to stall the target into "Standing Still for a minute", so the sniper can create advantage by taking an acting to put him "Centred In My Sights".

  Then the sniper free-tags all of those, for a base roll of +8 and a near-certain hit - with fate points to spare if he needs them.

  Stacking enough of this sort of this can greatly reduce plausibility, but it's obvious behaviour for a group of D&D players where it's an expected part of the system to need to stack every combat advantage you can generate. I don't, however, feel it's as much of a problem as some Fate players do - this is behaves-as-designed. Fate characters are supposed to be able to beat pretty much any single obstacle if they can generate a convincing narrative. "He's not that good a shot, but it worked because an entire team was helping him take it" is a pretty good narrative to me, and gives the plot and characters room to develop further.

• The "constant compels" problem arises when GM and players get caught in a Fate-point loop of constantly compelling aspects to force behaviour or non-actions from each other.

  Remind your players, and remember as GM, that the point of compels is to implement narrative development. The Fate point economy will naturally limit how far players can push this, so it's not a problem unless the GM gets sucked into constantly offering Fate for compels. So don't. Compel when it's a narrative or character development to do so, not just because it's possible.

• Long combats occur because groups have trouble actually taking out opponents of similar skill levels. This is particularly likely if your group is used to D&D, and trying to "wear them out" by all attacking individually. In Fate it's much more effective to set up a narrative about a couple of major attacks, taking multiple actions to support each other and make those go off well.

The best counter to most of these issues is threefold:

1. Let them have their moment. Players being able to tear through obstacles like this is not a problem in Fate the way it would be in D&D; it's expected behaviour of the system. Don't make it impossible, but ask what happens next and generate new obstacles. The problem can come more from a D&D-oriented GM feeling he has to make tasks "possible to fail" than from actual issues.

2. Your enemies are not idle. Don't GM in direct opposition to the player's actions, but instead change the game. Fate uses the same mechanics for social and combat conflicts, and it does so for good reason, expecting them to intermingle. Use it. Enemies will attack on social fronts, run away if they're in trouble, consult allies, adjust schemes, and all the other narrative options that are not often available to an orc in a dungeon.

3. Remember that in Fate, the player is always an informed participant, even when the character isn't. The gap between player and character knowledge is much bigger in Fate.

   Situation: A hostage is tied to a chair. There is a trap which incinerates the room if anyone touches the hostage.

   D&D answer: Tell the players nothing. Make hidden Perception checks. If anyone explicitly searches, make Search checks. Lie unless the players succeed at these checks.

   Fate answer: Tell the players immediately that there's a trap. Let them make rolls and use aspects freely to see if the characters spot it. If one of the players has a "reckless" or "rescuer" aspect, compel it - offering a fate point if their character runs in carelessly and sets the trap off. Make the players partners in decisions that hurt their characters.

When I read this:

On one hand he'd rather get "XP or something", but when I asked him if all he's really into is an arbitrary number he said "no".

My immediate reaction is to think "Of course he doesn't want an arbitrary number! He wants a meaningful number. That's the whole point of a progression mechanic."

So, your misunderstanding may be based on asking an innocent question that had a detail that wasn't important to you, but made the difference between a "yes" and a "no" for this player. Psychologically, arbitrary numbers are not rewarding nor feel like advancement, as there is no connection between one's actions and the outcome.

If the player is looking for "XP or something", they are quite probably looking for meaningful numbers in response to their actions and accomplishments during the game.

I understand this, being a huge fan of both strongly-narrativist play and of XP- and loot-rewarded dungeoncrawling. They're distinct flavours that have their own motivations for playing them, and the motives for one can't substitute for the other. If your player has only ever played a game with a tight action-reward loop, they probably feel lost with the lack of the familiar feedback system. They may quite enjoy a story-centric game, but like a missing limb, the lack of a reward mechanic will itch and be distracting.

So, concrete steps to take:

• Ask your player again, if "XP or something" means they want regular mechanical reward, i.e., "meaningful numbers" after play. If they do, then you've solved your understanding gap and can start figuring out solutions.
• Speed up the pace of your milestone rewards. If you're three sessions in and haven't hit a significant milestone (which is the "levelling up" mechanic in Fate), get a milestone in there as soon as possible. This player needs that feedback and sense of development. Yeah, Fate characters tend to develop laterally rather than upward, but anything is better than nothing.
• Focus more on the in-world effects of the players' actions overall. Are they gaining reputation? Adulation? Recognition? Players love to see the impact they have on NPCs, and if they're playing heroes, they should have hero-worshippers. This can go a long, long way to making a player feel like they're accomplishing something.