Base attack bonus
A base attack bonus is an attack roll bonus derived from character class and level or creature type and Hit Dice (or combinations thereof). Base attack bonuses increase at different rates for different character classes and creature types.
d6
A 6-sided die.
d20
A 20-sided die.
Whenever you attempt an action that has some chance of failure, you roll a twenty-sided die. To determine if your character succeeds at a task you do this:
Roll a d20.
Add any relevant modifiers.
Compare the result to a target number.
If the result equals or exceeds the target number, your character succeeds. If the result is lower than the target number, you fail.
Fortitude saving throw
These saves measure your ability to stand up to physical punishment or attacks against your vitality and health. Apply your Constitution modifier to your Fortitude saving throws.
Frightened
A frightened creature flees from the source of its fear as best it can. If unable to flee, it may fight. A frightened creature takes a -2 penalty on all attack rolls, saving throws, skill checks, and ability checks. A frightened creature can use special abilities, including spells, to flee; indeed, the creature must use such means if they are the only way to escape.
Hit dice
How many dice are rolled to generate the creature's hit points.
Hit points
Your hit points measure how hard you are to kill. No matter how many hit points you lose, your character isn’t hindered in any way until your hit points drop to 0 or lower.
Modifier
The modifier is the number you apply to the die roll when your character tries to do something related to that ability. You also use the modifier with some numbers that aren’t die rolls. A positive modifier is called a bonus, and a negative modifier is called a penalty.
MUD
MUD: Multi-User Dungeon; a text-based MMORPG. The difference between a MUD and an MMORPG is the same as between a book and a movie: MUD clients display (mostly) text; MMORPG clients display (mostly) 3D graphics. The difference is thus in the client: MUD and MMORPG servers work the same way.
Reflex saving throw
These saves test your ability to dodge area attacks. Apply your Dexterity modifier to your Reflex saving throws.
Round
A round lasts for 6 seconds.
Size
Skill check
When your character uses a skill, you make a skill check to see how well he or she does. The higher the result of the skill check, the better. Based on the circumstances, your result must match or beat a particular number (a DC or the result of an opposed skill check) for the check to be successful.
To make a skill check, roll 1d20 and add your character’s skill modifier for that skill.
Will saving throw
These saves reflect your resistance to mental influence as well as many magical effects. Apply your Wisdom modifier to your Will saving throws.