Unlike a nuzlocke however, in this challenge you are limited to only 15 pokemon in Gen I, 17 pokemon in Gens II-V, and 18 pokemon in gen VI.
For in this challenge, the player (you) can only capture one pokemon for each type. As soon as you encounter a pokemon of one type, this pokemon fills the "slot" in your type-chart, and no other pokemon of the same type can be caught. If the pokemon flees or faints, it still fills the "slot" (like in this chart for example)
You can also choose to play with or without dupes clause so in the same example:
*no replacements (if that wasn't obvious)
*if the hm slave is used as a meat shield same rule applies, and hm slave faints, rules above still apply
*Form change does NOT apply to wormadam
*No Items (or no items in battle)
*Dupes Clause (for dual types)
*Limited Pokemon Center Heals (1 in normal towns, 1 before gym and one after gym in gym towns)
*No repels (recommended)
*Starter can be ditched/wont count for type
*Dual types count for BOTH types
*Anything else you can think of!
If i remember correctly i tore yellow apart with a Dodrio XD
I'd replay it in a different region if someone makes a new thread for it