Alternatives To Ability Checks
In the fifth edition of Dungeons & Dragons, ability checks are the main system used to resolve actions and determine success or failure. In older roleplaying adventure games, there are alternative methods for resolving actions that do not involve using ability checks.
Basic D&D has a system for ability checks, as in later editions. It does not feature the skill systems of later editions, and so is much simpler.
Ability Checks
The referee may use a character’s ability scores to determine the character’s chance of succeeding at various challenging tasks.
Rolling an ability check: The player rolls 1d20 and, if the result is less than or equal to the ability, the check succeeds. If the roll is greater than the ability, the check fails.
Modifiers: Bonuses or penalties to the roll may be applied, depending on the difficulty of the task. A modifier of –4 would be a relatively easy ability check, and a +4 would be very difficult.
— Old-School Essentials
This ability check system in has a disadvantage compared to newer editions. In this editions, characters do not increase their ability scores as they progress in the game and their initial ability scores are usually average. As a result, most ability checks only have a 50% chance of success, which can be frustrating for players.
Players who are used to the newer editions of Dungeons & Dragons may try to use the ability check system in basic edition in a similar way, but may not have a good experience due to the differences in the system. However, there are alternative methods that can be used for various situations instead of using the ability check system.
Athletics
Consider the potential consequences of an action before deciding whether to use an ability check or an alternative method. For example, if the action carries the risk of instant death, a "save versus death" check may be appropriate. If the penalty for failure is delay or inconvenience, a "save versus paralysis" check may be a better choice. If there is no penalty for failure, the action can simply happen without the need for a check. For lifting heavy objects, it may be helpful to set a required strength rating and determine if the character or group has the necessary strength to lift it when adding together their ability scores.
Acrobatics
In later editions the Acrobatics skill is used to perform nimble actions such as running across slippery surfaces, balancing on tightropes, and maintaining one's footing in general. For most situations where Acrobatics would be used, it is recommended to allow the character to succeed or impose a penalty, such as a -2 to attack rolls, instead of requiring a check. If the action carries the risk of death or paralysis, a "death save" or "paralysis save" may be appropriate as with Athletics. Alternatively, instead of using a save, it may be more effective to alter the environment or how the character interacts with it.
Slight of Hand
A Thief will succeed at this automatically. No other class of adventurer should be attempting it. If it's being used to pick pockets, consult the thiefs percentille chance to succeed at this task.
Stealth
Stealth already exists within the game, and is handled by the rules for surprise. You can learn about this in the common skills and thief skills articles.
Arcana, History, Nature, Religion
Consider freely giving success to characters based on their class and level, as not knowing something can be less enjoyable for the player and less interesting for the story. For example, a Magic-User character should know a fact about arcana or may need to be a higher level to know it, a Thief character should know a fact about history, a Halfling or Elf character should know a fact about nature, and a Cleric character should know a fact about religion.
Investigation
Rules for investigation are covered by the Search skill, which allows characters to have a 1-in-6 chance of finding hidden objects in a 10-foot by 10-foot area. However, if a player character specifically describes searching in a location where something is hidden, the hidden object should be revealed. The Search skill is intended as a fallback for when characters spend time checking every possible location. If a character is described as carefully pushing each brick in a wall and a hidden door is opened by pressing a specific tile, the Search skill should automatically succeed without the need for a check or additional time expenditure.
Animal Handling
Make a reaction roll for the animal. Give a +1 bonus to the reaction roll if the character is an appropriate class such as Ranger.
Insight
In most cases, a character's disposition towards the party can be determined based on their reaction to the party. If the party is suspicious of someone, the players can ask about their body language and listen for any indications of nervousness or evasion, rather than requiring an Insight check to gather this information. As with knowledge checks, noticing important details is usually more engaging and interesting for the player than not noticing them.
Medicine
Treat this the same as the other knowledge skills.
Perception
Use a similar approach as for investigation, in addition to that, surprise forms the basis for perception and stealth, and so these both complement each other in using surprise instead of either skill.
Survival
Characters in an adventure should generally be competent and have the basic wilderness skills necessary for survival. For more specialized skills such as predicting the weather or tapping a tree for sap, consider the character's class and whether it is reasonable for them to have that skill based on what has been established about their background and experiences. For example, a Woodsman character should have a good understanding of the weather and a character from the far north should be able to recognize a crevasse.
Deception, Intimidation, Persuasion, Performance
Charisma checks can be replaced by using reaction rolls to determine the response of the character being influenced. In some cases, such as when the party is trying to intimidate someone, a morale check may be more appropriate.