Do you feel your character contributes greatly to the success of the party's endeavors?
[just by the way...when I originally posted these questions, they were intended simply as starting points for reflection...nothing more than that. I'm only elaborating on them to explain what I was thinking when I wrote them because, well, they may seem kind of cryptic without any explanation]
I'll try to keep this one short and sweet. What I'm getting at here is: do you feel like your character makes a difference...or do you feel the adventure probably would have proceeded the same without him or her.
The question is not one of accomplishment, the question is one of engagement. Remember, I'm talking about your subjective feelings. If you were recounting tales of your party's foray into some dungeon a few days after the fact, how prominently would your character's own exploits fare in the telling? If you feel engaged during play, then your perspective is likely to be colored by this, regardless of what your character actually "got done."
For me, as a DM, that's really the most important part. Some may say, "the whole point is to have a Good Time;" I'm just being a bit more specific in what I define as a "good time." When players feel engaged, when they feel a part of the game, when they can lose themselves even briefly in the joy of being an imaginary fantasy character...THAT is "having a good time."
If you spend the whole session saying, "damn, my character can't do ANYthing" and being miserable about it, then maybe the character you're playing is not the right one for you...because when it is, you find ways to get involved in the game.
Think of it this way: if you actually were a fantasy adventurer undertaking dangerous excursions into the unknown, what would you be doing? Well, that would depend on your skill set, right? What YOU bring to the table with regard to your character "classification?"
I'm not saying you need to be extremely proactive, A-type personality, all the time. I'm not saying your fighter character should be looking to pick a fight with every individual encountered in the dungeon. I'm suggesting that you should take a moment to think like your character class, though...and by doing so you should be able to find a way to contribute to the adventure at hand.
Especially because you'll know the strengths and weaknesses of your class.
If you can't do that, or it's not "fun" to do that, consider that this particular class may not be the one best suited for your personality and temperament. Class optimization is choosing a class of character that will allow you to optimize your fun and engagement in the game, by allowing you to express what you want to express in a role-playing game.
What follows is a brief thumb-nail of the seven classes of B/X, the usual roles they fill, and some of the personality markers that might designate the class as "optimal" for a particular person:
Cleric (personality aspect: Discretion)
Primary Roles: Second-Line Fighter, Specialist, Support
Clerics generally lack the hit points and damage output to be front-line fighters, though a high STR and CON score can change that at the low-mid levels. In general, the cleric player must understand discretion, holding back and waiting for the right time and place to act. Of all the character classes the cleric is the most "reactive"...the cleric's main duty to the party is to stay alive and well for when he/she is needed most (healing, turning undead, etc.). If you are not a "hang back and wait" kind of person, you may enjoy playing a different class.
Dwarf (main personality aspect: Ballsy)
Primary Roles: Front-Line Fighter, Mechanic
Secondary Roles: Scout
Dwarves are front-line fighters; their high hit points, good armor class, and prime requisite (STR) means they should be in the thick of any combat, leading the charge. They also have special abilities that make them good scouts in the dungeon environment. Dwarves are idea for walking "point" due to their infravision, ability to spot traps and shifty stone-work, and need to charge the enemy. If you don't like leading from the front, you may enjoy playing a different class.
Elf (personality aspect: Discerning)
Primary Roles: Second-Line Fighter, Mechanic, Support
Secondary Roles: Scout, Specialist (ghouls)
Elves are 2nd-line fighters. They do not have the staying power (hit points) of fighters and dwarves, and they also have mechanic/support abilities (spells) that need to be preserved for their best use. Though their infravision and secret door detection gives them some potential for scouting, they generally are too slow and have no concealment ability unless offset by spells. Elves ability to be both fighters and magic-users makes them a liability unless played by someone able to discern the best time to assume either role. If you don't feel you can make those judgments, you may find it more enjoyable to play a simpler character.
Fighter (main personality aspect: Fearless)
Primary Roles: Front-Line Fighter
The fighter is built for nothing less than front-line fighting. If your fighter cannot afford decent armor...well, you probably should be playing something other than a fighter. When the time comes to fight, you MUST be ready to step forward and do so, it is the only way your character "earns his keep." If you are the type that hems and haws when it's time for battle to be joined, you may enjoy playing a different class more than the fighter.
Halfling (personality aspect: Bold)
Primary Roles: Second-Line Fighter, Scout
Secondary Roles: Specialist (giants)
The halfling generally has the best armor class and saving throws of any of the classes, and often has moderate to good hit points, depending on Constitution score. However, their high dexterity and proficiency with missile weapons makes them a decided asset to the 2nd-line fighting role. It is important for the halfling player to understand that they are the "first line" of the "last line of defense." In outdoor settings, halflings are the ideal scout thanks to their concealment ability, and even underground they can squirm and fit places no other character can. If you're not ready or willing to take exploratory risks, you might enjoy playing another class more than the halfling.
Magic-User (main personality aspect: Ingenious)
Primary Roles: Mechanic, Support
Secondary Roles: Scout, Specialist
The role of the magic-user in a party will depend on two things: the spell selection of the character and the ingenuity of the player. More than any other class, the magic-user must be proactive in his approach to adventuring; he is never allowed the leisure of being reactive...even his selection of spells is done at the beginning of the day before he even sets foot in the dungeon. What's more, with his limited selection of spells the magic-user must find a way to be of use to the party outside of combat (which the wizard isn't really built for); holding light sources, directing hirelings, examining dungeon features for concealed levers and ancient writing. If you're not willing to be proactive, a magic-user is going to spend a lot of time sitting on his hands; you might enjoy a different character class more.
Thief (personality aspect: Adaptability)
Primary Roles: Mechanic, Scout
Secondary Roles: Specialist
The thief has many skills, none of which are useful for straight combat. Even the famed "backstabbing" ability will most often be used to "soften" a target...and without a supporting cast of fighter-types, a would-be assassin will usually be quickly mowed down. Thieves need to be ready to change tact depending on circumstance: infiltrating places others cannot, gathering intel when magical means of doing so are not possible, disarming/opening mechanical locks and traps, and getting to the back of the group when the real fighting starts. Thieves are probably the most tactical of the character classes, and need to be quick thinkers because of the situations they encounter. If you tend to have some inertia to your thought process, you may enjoy another class more than the thief.