Rance 01:Skills

Skills from ALICEMAN coins
Instead of damage and defence and other stats, levelling gives you 4 rewards: On its own, the coin can be used as a consumable to do 10 damage, which is terrible because you'll lose it and access to your skill!
 * Increase in HP
 * Increase in luck
 * Increase in inventory space
 * At levels 13, 16, 19, 22, 25 and 28, Willis will give you an "ALICEMAN copper coin"

You should bring the item in your inventory to the "Monument to the sage (聖人の碑)" (a blue card in Leazas field) where You will then be able to talk to the wild ALICEMAN that appears and select from a list of skills.

Trivia: 'sage' just so happens to be a pun for 'alien' in Japanese.

There are 6 skills to choose from.

It's recommended to get the Hyper metabolism and Fighting maniac 1st and 2nd, but don't fuss too much, as you'll eventually get all of them.

Sill
In addition to the ALICEMAN coin skills, there's a unique skill that you get automatically when Sill joins you. (TsuchiNoKao's note: unconfirmed and effects unconfirmed)