A Deep Dive into AD&D 2e Spells: Enlarge / Reduce

1st Level Spells, Advanced Dungeons & Dragons, Old School, Spell Deep Dive, Wizard Spells
  • Level: 1
  • Range: 5 yards/level
  • Components: V, S, M
  • Duration: 5 rounds/level
  • Casting Time: 1
  • Area of Effect: 1 creature or object
  • Saving Throw: Neg.

When discussing the Alteration school, the focus often drifts to flashy high-level spells like Polymorph or Telekinesis. However, veteran players know that Enlarge (and its reverse, Reduce) is one of the most mechanically robust and scalable 1st-level spells in the entire AD&D 2e system. It is not just a combat buff; it is an engineering tool, a siege weapon, and a master key, all dictated by a strict set of proportional mathematics.

Functional Overview

The spell targets a single creature or an object (up to 10 cubic feet per caster level) and alters its physical size and mass.

  • The Math of Growth: The target grows by up to 10% per level of the wizard. This increase applies to height, width, and weight.
  • Damage Scaling: Hit points, Armor Class, and attack rolls remain unchanged. However, damage rolls increase proportionately with size. A 6th-level wizard enlarging a fighter by 60% turns a longsword strike of 6 damage into 9.6 (rounded up to 10).
  • Equipment & Magic: Worn equipment scales with the creature. However, magical properties do not intensify. An enlarged Potion of Healing doesn’t heal more; it just requires you to chug a gallon of liquid to get the same effect.
  • The Constraints of Space: You cannot crush a creature to death by enlarging them in a tiny room. They will burst “weak enclosures” but be safely constrained by stronger materials like solid stone.
  • The Reverse (Reduce): The target shrinks by 10% per caster level. The scaling rules here are notoriously granular: it drops in 10% chunks, then 1-foot increments, then 1-inch increments, and finally 1/10-inch increments. You cannot shrink something into nothingness.

Deep Research: Tactical Insights & Exploits

Combing through decades of tactical forums and legacy rulings reveals that Enlarge/Reduce is highly exploitable when you apply real-world physics to its mechanics:

1. The “Piton Breach” (Structural Sabotage)

The text explicitly states that an enlarging object will burst “weak enclosures.” While a wizard cannot crush a goblin inside a stone corridor, they can use this offensively against architecture. A classic old-school tactic is driving a standard iron piton or wooden wedge deeply into the crack of a locked heavy wooden door or a weakened masonry wall, and then casting Enlarge on the piton. The sudden 50%+ expansion in mass and width acts as a silent, instantaneous battering ram, bursting hinges and cracking stone without the noise of a Knock spell.

2. The Late-Game Fighter Multiplier

Unlike Sleep or Color Spray, Enlarge actually gets vastly more powerful at higher levels. Because the growth is 10% per level, a 10th-level wizard increases a creature’s size by 100%. This literally doubles the base weapon damage of the party’s frontline fighter. Casting this on a specialized fighter wielding a two-handed sword before a boss fight yields a higher sustained damage output than almost any direct-damage 1st-level evocation.

3. The “Ant-Man” Infiltration (Reduce)

High-level uses of the Reduce spell turn the party rogue into an unparalleled infiltrator. A 10th-level wizard can shrink a human thief down to mere inches. At this size, the thief’s weight is practically negligible. They can walk directly over pressure-plate traps without triggering them, slide under the gaps of locked doors, or be carried over a fortress wall by the wizard’s raven familiar.

4. Instant Barricades

Because Enlarge affects weight, mass, and strength, it is the ultimate tool for securing a retreat. Flipping a standard wooden tavern table in front of a door provides decent cover. Casting Enlarge on that table increases its mass and dimensions so drastically that it wedges itself into the doorframe, transforming from a temporary obstacle into a vault-grade barricade.

Research & Acquisition

Enlarge/Reduce represents the foundational theory of mass alteration.

  • Research Time: 1d10 + 1 weeks.
  • Financial Investment: 100–1,000 gp.
  • Material Components: A pinch of powdered iron. (Some DMs require a pinch of powdered iron to Enlarge, and a pinch of powdered lead or a smaller, mundane counterpart to Reduce).

Theoretical Variants

Wizards who specialize in physical manipulation often push this research into specialized directions:

  • Targeted Hypertrophy (Level 2 Research): Rather than enlarging the whole creature, this spell targets only a specific limb or weapon. It grants the damage multiplier without making the creature a massive, easy-to-hit target for enemy archers.
  • Mass Reduction (Level 3 Research): Affects an area rather than a single target. While the scaling factor is capped at a flat 50% reduction, it can be cast on a charging squad of orcs, halving their movement speed and halving their physical damage output in a single action.
  • Permanent Stature (Level 4 Research): A difficult variant that permanently alters a creature’s size by a maximum of 10% (either taller or shorter). It is often utilized by vain nobles, disguised spies, or adventurers looking for a permanent minor edge in reach or stealth.

The Verdict

Enlarge/Reduce is a masterwork of scalable game design. It requires players to do a bit of math at the table, but the payoff is immense. At 1st level, it is a clever utility tool for bursting locks and creating barricades. By 10th level, it is a premier combat buff that turns the party’s martial characters into unstoppable, double-damage dealing siege engines.