This article is from the Final-Fantasy and other Square Soft Games FAQ, by firstname.lastname@example.org (Nick Zitzmann) with numerous contributions by others.
Each gear can perform combos which usually become available after their
pilots have learned similar combo moves. To reach the higher levels of
gear combos, your character needs to learn the more powerful 6 AP
attacks. (The 7 AP attacks don't do anything for your gears.)
Once you have some combos, simple fighting will raise the gear's attack
level. For each time a gear attacks but does not use a combo, if the
pilot has learned the required prerequisite combos, then the gear's
attack level will rise.
(NOTE: There are two exceptions to this rule. Seibzehn begins the game
with the ability to reach attack level 3 without any pilot
prerequisites, and Chu-Chu is incapable of performing combos.)
Attack levels always start at zero. At level 1, the gear can use one of
two possible weak attack combos. Level 2 enables up to two medium attack
combos, while level 3 enables up to two fierce attack combos.
How to gain attack levels: Level 1 requires each character's first two
4-point attacks, level 2 requires the first two 5-point attacks, and
level 3 requires the first two 6-point attacks. What about the remaining
three attacks? They can be performed, but only if the gear is equipped
with accessories called "DeathBlowers." For example, the DeathBlower1
will give the gear an additional level 1 attack if the character has
their third 4-point attack.
Attack level is appropriately decreased when using a combo. For example,
a weak combo will decrease the attack level by 1, while a fierce combo
will decrease the attack level by 3.
Now that we've briefly described gear combos, note that there is one
additional attack level. The "infinite" attack level allows your
character to execute one of three devastating fuel-efficient attacks,
but it only lasts for three turns. Charging while in infinite attack
mode restores several times more fuel than normal.
Your characters can not enter infinite attack mode until after you have
defeated Achtzehn at Shevat during disc 1. After this, each character
will have their limiters removed, which will allow them to enter this
To reach infinite attack level, your character must be at attack level 3
during a battle. They then have a random chance of reaching infinite
attack level. The gear's chances of reaching infinite attack level are
increased when it does or takes damage. In other words, the more damage
done or taken by an attack level 3 gear during battle, the greater the
chance of the gear reaching infinite attack level. Usually, infinite
attack level kicks in after a gear's "hyper mode" has reached about 60%
Each character has up to three infinite attack level moves. The other
two become available as the character increases in level, which should
happen around levels 50 and 60 or so.
(This is true for all gears except for Weltall-2. With Weltall-2, you
can take the normal approach to reaching the infinite attack level, or
immediately enter infinite attack level by using the special "System Id"
Also, Xenogears (and only Xenogears) is in a permanent 99% hyper mode.
This means that after reaching attack level 3, if you make one more
attack without using a combo, then Xenogears will immediately enter