Isaac speaks first of family when you ask about him. One of five children, his family knew poverty, and stealing was not condoned, but encouraged. But Isaac yearned for more honorable pursuits, and he was proud to found the Planar Hunter's alongside his friends, Mavis, Ivan, Bernadette, Caim, Demetria, and Frederick. But the friendships soon ended when Mavis murdered Frederick. Isaac swore revenge. No matter what it takes, no matter how many lives, he desires nothing more than to see Mavis pay.
Isaac is a man who values honor, and though his methods are ruthless and sometimes cruel to achieve his ends, he values the systems of order and only wishes to expunge what he believes corrupts Faerun, the meddling of devils, demons, and their spawn. In balance, so must the spawn of any outsider be removed. This puts him against people like Haer'dalis, Sirene, and Emily. However, his loyalty to the PC encourages him to respect who they bring along, though displease him too much, and he may leave of his own choice.
Isaac has his own kit, but he can also use the Artisan's Invisible Blade Kit if installed.
INVISIBLE BLADE: The invisible blade, sometimes called dagger masters, are deadly rogues who prefer to use tiny blades, especially daggers, in combat. Able to find the most lethal stabbing points, they enjoy a frightful reputation, able to kill skillfully and gracefully while forgoing the encumbrance of armor entirely.
-May achieve grand mastery (5 slots) in dagger.
-While wielding a dagger, gains +5% critical chance and +1 to THACO.
-Adds Intelligence to Armor Class in addition to Dexterity.
-May use the Bleeding Wound ability once per day. Gains one use at level four, and then every four levels thereafter.
BLEEDING WOUND: Each successful hit within the next five rounds will cause additional 2d4 bleeding (piercing) damage after one round. The number of rounds the additional bleeding damage occurs increases with level.
1st: 2d4 bleeding damage after 6 seconds (Save vs. Death negates.)
5th: 2d4 bleeding damage after every 6 seconds for 12 seconds. (Save vs. Death at -1 negates.)
9th: 2d4 bleeding damage after every 6 seconds for 18 seconds. (Save vs. Death at -2 negates.)
13th: 2d4 bleeding damage after every 6 seconds for 24 seconds. (Save vs. Death at -3 negates.)
-May use the Uncanny Feint ability once per day. Gains one use at level one, and then every four levels thereafter.
UNCANNY FEINT: Each successful hit within the next five rounds will surprise the enemy, lowering their missile and piercing armor by -1 for 4 rounds with no save, stacking. Additionally, if wielding a dagger, gain half an attack per round at level 7, and a full additional attack per round at level 15 for the duration.
-May not wear any armor.
-May not wear gauntlets or bracers.
-May not use ranged weapons except throwing daggers and other thrown weapons.
-May only distribute 20 skill points per level among thieving skills.
Disposition & Approval
Isaac will have an approval system in both BG1 and BG2, just like Recorder. Despite being a thief, he values loyalty and honor, and has an appreciation for those who does anything it takes to achieve their ends, no matter how dark.
He gets along with everyone, however, even Ajantis, though he is careful how he speaks to him to ensure he is not struck down.
He gets along the least with Emily. Expect some rockiness if you keep them both around in BG1, and if not careful, eventual conflict. BG2 is a bit better, but his quest can conflict with Vienxay's, so you may be forced to choose who to please first.
In BG1, Isaac and his fellow Planar Hunter will ambush the party upon leaving the world map of the Friendly Arm Inn.
In SoD, he appears when going towards the camp after talking to Caelar across the bridge.
In BG2, Isaac appears when you leave the slums for the first time.