The Monster Builder is a Flash tool that helps DMs generate stats and attacks for standard monsters from levels 1 to 40. It is intended for people who can’t install the D&D Monster Builder application of the D&D Adventure Tools, and it is neither as robust nor as versatile as that application.

Enter the monster's name, capitalized. Set the monster's level, choose its role, and choose its primary attack ability. These choices will determine most of the monster's default stats. Choose which basic attacks it will have, and select its size, origin, and type. As you make choices for your monster, the stat block fills out step by step. Click Next to proceed.

This screen presents the monster's default ability scores, plus the stats derived from the monster's level, role, and abilities. By default, one of the monster's defenses will be 1 or 2 higher than normal, based on which ability score is higher than average. You can alter any ability score up or down. Beasts and animates in particular often have low Int scores. When altering ability scores, be careful not to raise or lower the monster's Fortitude, Reflex, and Will defenses too far from standard. The "Deviation from Standard" column lets you keep track of how the changes you've made affect these scores. While not listed on this screen, adjusted ability score modifiers and thus skill bonuses also increase or decrease with ability scores.

By default, your monster has a melee basic attack, a ranged basic attack (if you selected it on the Level & Role screen), and one limited-use attack power per tier. You can use the "+" tab to add more powers, for up to six basic attacks and powers total. Name each basic attack or power and define its recharge (if any). Then define the attack type, its area (if any), and the defense that it targets. The system automatically calculates an attack's bonus and damage, based on the monster's role and level and on the type of attack it is. Optionally, you can add keywords and notes for each attack.

For a controller's attacks, add some sort of control effect, such as forced movement or daze.

To give your monster a non-attack power, such as a bonus for combat advantage, or a custom attack power, such as an immediate reaction, select Custom from the attack type. You then have total control over the power's action type, recharge, and effects.

This screen has several miscellaneous fields for you to fill out, each labeled. Clicking on the Perception button makes the monster skilled in Perception (+5 to bonus). The information on this screen includes several optional items that you can ignore, such as aura. It also includes information that isn't strictly optional but that's not needed for most simple fights, such as alignment. The speed field on this screen is the one piece of data that you need in order to use the monster in a fight.

This screen has three fields for text describing the monster. The first is a general description. The second is for combat tactics. The Lore field is for you to define what skills the characters can use to know relevant details about the monster. The list below tells you which knowledge skill is relevant for your monster (plus Religion if it's undead). If you don't want to have one of these fields in your stat block, delete the text in the field. For Tactics and Lore, the header will disappear from the stat block if there's no text in the field.

Origin or Keyword - Knowledge Skill
aberrant - Dungeoneering
elemental - Arcana
fey - Arcana
immortal - Religion
natural - Nature
shadow - Arcana
undead - also Religion

Here you can see the stat block. You can select the text and copy it to paste elsewhere. The Formatted View button generates a formatted popup with the stat block in it. Using your browser, you can print the stat block or save it as an HTML file.