Psionics for Labyrinth Lord

(Note: this houserule for Labyrinth Lord uses the traditional ability modifiers originally found in Basic DnD. If you don't know what those are, they are as follows:

• 3: -3
• 4-5: -2
• 6-8: -1
• 9-12: 0
• 13-15: +1
• 16-17: +2
• 18: +3

Psionics is something not everybody likes. I like the aesthetic of it, but I don't quite like it in ODnD or ADnD, so I made my own thing, inspired by both of them! This is best used with the AEC, but you can use it with default LL if you want.

Determination of Psionic Ability

The chance of a character having psychic powers is equal to their base chance based on their race plus the highest of their INT, WIS, or CHA modifiers, multiplied by 5. You then roll 1d100, and if it is equal to or below the probability generated earlier, your character has psionics. The base chances of psionics in the races of the AEC is as follows:

• Dwarf: 15
• Elf: 2
• Gnome: 12
• Halfling: 10
• Half-Elf: 5
• Half-Orc: 10
• Human: 10

Mental Prowess

You gain levels in your psionic ability separate from your class levels. This uses its own XP chart, with the XP you gain being split between mental prowess and class levels as you wish. The leveling chart for mental prowess is as follows:

1. XP: 0
2. XP: 1,500
3. XP: 4,500
4. XP: 6,000
5. XP: 13,500
6. XP: 22,500
7. XP: 33,000
8. XP: 45,000
9. XP: 58,000
10. XP: 13,500/level after ninth

Psychic Powers

As you gain mental prowess, you will gain eldritch psychic powers. You begin with 2, and gain 1 more for each level you gain in mental prowess. The first two powers you learn do affect your ability scores as noted below, but they do not affect your class abilities as noted below unless there is something below level 1, such as is the case with the fighter.

When you learn a psychic power, you can either opt to gain a new power, or you can gain another use of a power you already know. Both options affect your abilities the same. All powers affect non-psions, but non-psions cannot retaliate.

A list of psychic powers is provided below.

Affect on Abilities

Your ability scores and class abilities are affected by your increasing in psionic power. Each class is affected differently, with the effect on its abilities being noted below. If any classes seem like they are different from what they are in the AEC, that is because I have changed them into a more streamlined form.

Assassin: For every psionic power they learn, they lose 1 level of assassination ability.

Cleric: For every psionic power they learn, they lose either 1 spell or 1 level of turning ability.

Druid: For every psionic power they learn, they lose either 1 spell or 1 level of shapeshifting ability.

Fighter: For every psionic power they learn, they lose 1 level of combat ability.

Illusionist: For every psionic power they learn, they lose 1 spell.

Monk: For every psionic power they learn, they lose 1 level of all of their abilities (not saves/combat ability).

Paladin: For every psionic power they learn, they lose 1 level of all of their abilities (not saves/combat abilities).

Ranger: For every psionic power they learn, they lose 1 level of their ranger skills.

Thief: For every psionic power they learn, they lose 1 level of their thief skills.

Wizard: For every psionic power they learn, they lose 1 spell.

Your ability scores are also affected. Your Strength, Dexterity, or Constitution score decreases by 1 for every 2 powers learned, and your Intelligence, Wisdom, or Charisma score increases by 1 for every 2 powers learned.

Psychic Defenses and Attack Bonuses

The defense used in psychic combat is Mental Strength, or MS, which is calculated as follows:

• (ascending) 10+the highest of your Intelligence/Wisdom/Charisma modifiers+your mental prowess
• (descending) 10-the highest of your Intelligence/Wisdom/Charisma modifiers-your mental prowess

The attack bonus used in combat (when using ascending MS) is equal to the highest of your Intelligence/Wisdom/Charisma modifiers plus half your mental prowess. If you are a member of the monk class, it uses your full mental prowess, rather than half of it.

When using descending MS, you must use a combat matrix like that in the ADnD Dungeon Master's guide. I will not be making one here, but a good bet is the one for the fighter in default LL.

List of Psychic Powers

Mind Blast: The most common and most basic psychic power. It emits a 30 ft. long cone that deals 1d8 damage to anything that enters it. The damage increases by 2 points for every level of mental prowess you gain.

Explode-a-Head: This power attempts to blow up the head of the target. It can only target creatures that you can see. You must make an attack roll against the target, and if it succeeds, the target must make a saving throw vs. death. If the save fails, they instantly die. If the save succeeds, or the attack roll fails, they take 1d6 damage.

Mind Blank: This power makes your mind invisible to other psychics, making you unable to be targeted. You make a check on the lowest of your three mental ability scores, and if it succeeds, you cannot be targeted by psionic attacks.

Mental Barrier: This power makes it harder for mental attacks to hit. It makes your MS 15 (if using ascending) or 5 (if using descending), unless it is better. This number increases by 1 every level of mental prowess you gain.

Animal Telepathy: You can speak to 1 type of animal of your choice. You can choose another type when you gain levels in mental prowess.

ESP: You can read the minds of those around you. Most metals block this. When you gain levels, you can choose metals that normally stop ESP to cease this defense. The only ones that always protect are aluminum and lead.

Telekinesis: You have control over your environment. You can manipulate 1 object, but gain the ability to manipulate 1 more for each level you gain.

Comprehend Languages: You can understand everything that all people you can hear say. You cannot understand all writing.

Precognition: You can see a few seconds into the future. For every level you gain, the time you can see into the future increases by a minute.

Psionic Wandering Monsters

If you are engaged in psychic combat, there is a 15% chance that a psychic monster will appear the next turn. For every psionic power you use, this increases by 10%. Monsters that may appear include beholders, mind flayers, certain oozes, golems, thought eaters, demons, phase spiders, or other psions.