Personally I am partial to this one:
Simplified Collaborative Neutral Rules
A. An attack by any Axis power upon any territory within a Neutral Block will result in all territories and armies within that Block immediately joining whichever Allied power the Allied player chooses. An attack by any Allied power upon any territory within a Neutral Block will result in all territories and armies within that Block immediately joining whichever Axis power the Axis player chooses. The six Neutral Blocks are:
1. South America (VEN, COL, ECU, PER, BOL, PAR, CHI, ARG, URG)
2. Iberia & Africa (SPA, POR, ANG, MOZ, RDO, PRG, SIE, LIB)
3. Islamic (TURK, SAUD, AFG)
4. Mongolia (OLG, DZA, TSA, CMO, ULA, BUY)
5. Sweden (SWE)
6. Switzerland (SWI)
B. The United States Continental NO is now called the World Trade NO. If the United States attacks any strict neutral, it may never again collect this NO.
C. An attack by an Axis power on any strict neutral territory while the USA and/or USSR are not yet at war will result in USA and USSR immediately joining the Allies.
I would like to also add this to it if you don’t mind:
D. If an axis power attacks Turkey when it is a strict neutral, the Soviet Union preemptively destroys oil production facilities in Azerbaijan, and Germany may never again collect the 5IPC NO for Caucasus oil.
z110
a
Rolls: 1@2, 3@3, 4@4; Total Hits: 31@2,: (3)3@3,: (1, 4, 4)4@4: (5, 4, 6, 4)
d
Rolls: 1@3, 1@4; Total Hits: 11@3,: (2)1@4: (6)