Gens 1 & 2: Refactor secondary status effects.
After a review of the disassembled code of gens 1 and 2, we've come to realise some very important stuff regarding secondary status.
On gens 1 and 2, Fire-types are not inherently immune to burn.
Ice-types are neither inherently immune to ice.
On gen 1, secondary status effects for paralyse, burn, and freeze will be ignored if the target Pokémon shares a type with the move-type.
On gen 2, the same happens but only for burn and freeze.
Poison-types are actually immune to poisons.
On gen 2, tri-attack can burn fire-types and freeze ice-types.
On gen 1, body slam cannot paralyse normal-types.
Also, Lick cannot paralyse ghost-types.
And thunderbolt/thunder can't paralyse electric-types.